Don't become on the information superhighway!. Read what is on the other pages at this site and look at the questions and answers below. They have been sent to me by some of your fellow students in the US and world wide wanting help on their school papers. You can also post questions to me and I may answer them and place your questions on this page too!
Just remember your teachers can search the web and find this page also. If you copy my answers word for word that is plagiarism and you will eventually be caught. Copying my words is just as bad as writing your report on frogs straight out of the Encyclopedia Britannica. Your teachers can spot the difference between my writing and yours!
By the way, if you write to me, please use your own Email account and make certain that your Email address is correct, otherwise, you might not get that A that we so richly deserve. In cases where the Email fails, I will try to post your questions and my answers on this page in a timely fashion.
hello I'm a student in a high school in Issaquah Washington and I'm doing a report on Huntington Disease. I was wondering if you could help me out by answering some questions.
1) How did this "abnormality" happen?
There exists an instability or error when the chromosomes reproduce, probably in sperm production (e.g. only in paternal descent is there anticipation or an increase in the number of CAG repeats). This probably started as a random mutation with a 'founder' effect. That means that someone back probably in the 1600's had the original mutation.
2) How is it passed on?
Each chromosome has two alleles. One you got from your mother, the other form your father. You only need one HD allele to get the disease. If you inherit the HD allele (a.k.a. the HD gene) you will get the disease if you live long enough.
3) What is the chance of getting?
For each child of a HD parent the chance is 50 % of inheriting the gene. If you get the gene, you will get the disease if you live long enough. There is no carrier state.
4) How many people in a given population have it?
In North America the best estimate is 25-30,000 people with HD and 125,000+ at 50% risk. Population rate varies from very high (7,000/100,000) in the Lake Maricibo region of Venezuela to low (2/100,000).
5) Is there a chance for a cure and/ or early detection?
Pre-symptomatic detection of the gene is possible through a DNA test. This test is only offered for those at risk who are adults. Strict guidelines and licensure through the HDSA is used in North America. For a good discussion of the ethical problems of genetic testing please see the April or March Scientific American.
6) How would this affect your life if you had this disease?
-talking care of yourself
Anything from inability to do sequential task (Sort clothes to coloreds and whites, wash coloreds in cold water, put in dryer, then wash white sin hot water, put in dryer while folding coloreds), to clumsiness making it difficult to perform simple tasks to the chorea interfering with your ability to do things.
-relationships with other people
Social isolation is one of the biggest problems, other areas include paranoia, explosive personality traits, lack of restraint on emotions...
-on your hobbies, sports, social activities
diminished ability to participate in some sports, continued ability to observe
With behavioral problems grades can go down as they can to a lesser degree with the cognitive problems.
From Brent Huntington (no relation to the disease) PS: I'm sorry to bother you and if you can not answer these questions please give me an e-mail address that can help. Thanx again.
Good luck on your report.
From Keith David at AOL.COM we have:
I am doing a report on Huntington's Disease. One idea we have to include is how the environment plays a role in HD. If you could give me a direction on where to search, or even an answer that would give me a sense of how the environment would play a role it would be greatly appreciated.
Please respond as soon as possible. Thanks!
The environment plays no role in the genetics of HD. It can play a role in the development of a person who has the gene. In our physical and emotional development we acquire the skills to deal with what happens around us and to us. If those skills are not learned because of a poor childhood environment than the person may not be able to face Huntington's Disease as well as one who was able to learn those skills.
From Charles Perrier at computer-services.com we have:
I am doing a Composition II research paper on the Human Genome Project and what they have found concerning Huntington's disease. Do you have any information that could help me? Are they doing any type of gene therapy for the disease? Do you have an example story on a person with Huntington's disease and how it effects his/her daily life?
INIT 15, the HD gene was sequenced outside of the Human Genome Project. By going to me web page, you can find a pointer to OMIN and to the NLM and be able to view the gene sequence.
Gene therapy has not yet been tried in HD and probably will not be any time soon, since the affected portions of the brain are rather difficult to get to even with adenovirus vectors.
If you wish to find how HD has affected a person, try the HD list server or look at the life of Woody Guthrie.
From Sharon Cheeks at aol.com we have:
Hello. My name is Sharon Chen. I am a research student here at Bronx Science in New York. I am doing a term paper on the use of human fetal tissue for a cure. I was wondering if you can e- mail me a detailed explanation on a procedure along with the materials and methods in which you have transplanted human fetal tissue.
I am not involved in the fetal tissue research, but have followed the literature with interest. The basic idea is that the fetal mesencephalon (the part that will become the basal ganglia) is dissected from a fetus, tested for transmissible diseases and then pooled with the tissue from other fetuses for transplantation into the caudate nuclei and putamen.
I would also appreciate it if you can please e- mail me background notes on this disease.
Please read my home page and look at some of the pointers on the page. So far, I have done my research on this and I know it affects the ganglia in the brain which causes involuntary, jerky movements. It is a hereditary disease and the gene was found that causes this disease in 1993. For my report, I have to have a procedure, materials, methods, results, observations, and anything else that deals with the use of human fetal tissue.
You may wish to visit the NIH clinical center home page (NIH.gov) and look at some of their postings regarding fetal tissue research for the background material that you need.
From Jay Geveshausen from Meadowdale High School in Washington we
have: Dear um..um I DON'T KNOW YOUR NAME!!,
Oh well. I am a nineth grader at Meadowdale High school in Lynnwood Washington. I found your page very helpful but I found it much late my grandmother died of HD in November of 95'. I just wanted to share my experience with you. I never really saw my Grandma when the effects of HD were not there. You describe that with HD there is a lot of moving that the person does, fidgeting for example. I never saw my Grandma do that my parents said that it was the medicine that she was on that made her stop or not even start. But there was one other thing that I saw in my grandma that I am not sure that I saw on you page ( I probably just read over it and missed it) the fact that there is a constant wanting to go out and do things. Like for example my grandmother went to the mall everyday for just about 12 yrs. went out to dinner for 10 yrs and everyday they ( my grandparents ) came over to the house at 6:28 pm would stay for ten minutes and leave 8 1/2 yrs. I wish I had been more educated on this subject but I did want to think about something that I might possibly could of had if my father was not adopted. Every thing was just so routine. I would hope that you take my example and use there is just so much more I could tell you but I don't want to bother you anymore
PS I got an a on my health report that I did on HD and I used your page only !!
From Charles Dean we have:
< Date: Thu, 12 Sep 1996 18:49:25 -0400 (EDT) From: Charles.Dean@Washcoll.EDU Please send me the name of a famous person with Huntington's Disease. I need to know for a school project.
How about Woody Guthrie?
< Date: Fri, 13 Sep 1996 14:14:00 -0400 (EDT) From: Charles.Dean@Washcoll.EDU
Thank you for the name of Woody Guthrie. My teacher congratulated me for
replying to his question so quickly. I wish you luck and continued success
in your line of work. I have always wanted to visit Kansas.
From Barbara Beccue we have:
I'm a freshman at University High School, Normal, Il. I'm researching 4 different disease for my wellness class. One of them is Huntington's Disease. One of the items that I'm supposed to report about is the cost of treatment for the disease. So far I have not been able to get an estimated cost or cost range. Could you give me some idea of how much it would cost to treat someone with Huntington's &/or what some of the major costs are?
Thanks, Tim Beccue
Early disease, doctor's visits and medications should run under $2,000/year, closer to $600/ year. Diagnostic costs may range from an office visit ($150) to DNA testing ($265) to an MRI ($1200).
Moderate and late disease are more expensive when home aides are needed ($12-15,000/year) or when a nursing home is required ($25,00/year). Medicare helps to pay for home health aides and nursing home costs.
At the movement no treatment that is curative is available, only symptomatic. These medication costs could vary from $100 to $3,000/year expending on the medications. Once again, some insurers may help to cover these costs.
From Chris Ware, a medical student at Allegheny Medical School, I had several questions about the pathophsyiology and treatment of HD.he had the audacity to call me directly several hours before his report was due and just a few hours before my grant application was due. He deserve cudos for his audacity and some derision for waiting until the last minute for me to bail him out. The good news was that he was grilled by a friend of mine who is a fellow HD researcher.
From Stacy Klingberg we have:
Dear Dubinsky I am doing a report on Huntington's Disease for school. This is the stuff I need to know:
I. Introduction - What is the name of the disorder? Are there any other names by which it is commonly known?
Huntington's disease or Huntington's chorea
II. Mode of inheritance - All genetic disorders are inherited. There are several different ways in which they can be inherited. Determine whether your disorder is an autosomal dominant trait, an autosomal recessive trait, an X-linked recessive trait, a chromosomal error or a multifactorial trait (polygenic disorder). Chromosomal errors may take several types: a particular missing chromosome (e.g. a missing X chromosome), an extra chromosome (e.g. an extra chromosome 21), or a damaged chromosome (e.g. part of a chromosome deleted). A multifactorial disorder is one which is caused by several genes or by a combination of genetic and environmental factors. Autosommal dominant with complete penetrance
III. Clinical description of the disorder - What are the features of the disorder? How does it affect the victim? What is it like to have the disorder? How would you describe the disorder to someone else? What is the disorder like externally, internally, biochemically, psychologically, etc. What problems are associated with the disorder? Is the disorder physically limiting? Is it life-threatening? Is it invariably fatal? Is it found more commonly in certain groups of people, such as a particular ethnic or religious group or particular sex?
Please see my web page:
Introduction to HD
IV. Treatment - Can anything be done for the disorder? Can the basic defect be treated? Can the symptoms or results of the disorder be treated? Is there a cure for the disorder? Is there any gene therapy for the disorder?
No specific treatment is available, symptomatic treatment is available. Please see: Behavior and HD
V. Detection - Can the disorder be detected before its symptoms appear? If so, how? Can it be detected prenatally? If so, how? Is there any way to detect a carrier of the disorder? If so, how?
Genetics of HD
Thanks for helping,
When in doubt, read the information provided first.
From Connie Donley from the land of OZ (not Kansas) we have:
My son is doing research on Huntingtons Disease, and he needs to include a Punnett square in his report. If one parent has the HD gene the chances are 50 50 that the child will inherit HD--if both parents carry the HD gene, would the chances be 75%? If you could e-mail a punnett square I would appreciate it--Thanks, Connie
Dear Ms. Donley,
I am not certain what a Punnett Square is, but I think that I can answer your question. If one parent has the HD gene and the other does not, each offspring has a 50% chance of inheriting the gene and developing the disease if they live long enough. Each grandchild of that couple has a 25% chance of inheriting the gene and developing the disease.
If both parents have HD (a rare occurance even in Venzuela where the incidence is much higher) than you are correct that each child has a 75% chance of inheriting one or two copies of the HD gene and eventually developing the disease.
From Alex Plocik we have:
Hi, my name is Alex Plocik, and I am a college student writing a reseach paper on Huntington's disease. I have been researching the major journal publications on the biochemical and genetic apsects of Huntington's disease. As part of the paper, I would like (and required) to have some sort of non-written source.
Whatever your credentials may be, your interrest and dedication to inform about Huntington's disease clearly puts you at the top of my list of people to attempt to interview on the subject. So, I was wondering if you would comment on the questions below with your opinions or knowledge. If you wish not to participate, that is fine, your web site has been very helpful in of itself. Thanks.
If the cause of Huntington's disease is determined, what then will researchers do to find a cure?
Try to thwart the course of the disease. There are many possibilities including delaying or preventing the onset, slowing or halting the progression and even reversing the course of the disease.
Why is Huntington's disease so prevelent?
HD is a fertile disease, in that the disease itself does not prevent having children.. This means that those who have the gene may not manifest the disease until after they have had children,thus potentially passing the disease to another generation.
Have their been cases where Huntington's disease has occured with
seemingly no family history?
Yes. The genetic term is anticipation. The number of CAG repeats on the INIT 15 gene can expand from generation to generation, usually, but not always with descent through the father. A parent may have a INIT 15 allele with 33 to 35 repeats and their child may inherit an expanded allele with 40 or more repeats.
As Huntington's disease progresses, do the symptoms of the disorder
Yes, as the disease progresses there may be less choreiform movements, more stiffness, rigidity and dystonia, more problems with behavioral problems and a decline in cognition.
What is the most effective way to care for a Huntington's sufferer
so that they feel as comfortable and self-sufficient as possible.
Maximize their ability to care for themselves and to remain independent.Help them to do things that they find meaningful.
Also, could you please leave your name, and any credentials you
Please see my c.v.
Thank you very much, this and the web-site have been very useful to me in focusing my research. Thanks again, Alex Plocik.
From Rona Claus we have:
Hi I am a freshmen at Wapahnia high Shcool. I am doing a report on the Huntington's disorder and I am looking for information on current resurce for this disorder. If possibl please send me some Information as soon as possible. I chose this subject because my dad may have it. Rona Claus
First,try reading our site: http://www.kumc.edu/hospital/huntingtons/ From there you can follow the link to the HDSA site: : http://neuro-www2.mgh.harvard.edu/hdsa/hdsamain.nclk And also visit their page that lists local support groups and HD clinics: http://neuro-www2.mgh.harvard.edu/hdsa/wheretofindhelp.nclk If you feel that you father may have it, please look carefully at all of the information about the genetics of HD.
Good luck on your report.
From Michael Sothmann we have:
My name is Michael Sothmann from Bundaberg, Queensland, Australia. I am doing Huntingtons disease for a biology assignment and need some help with the following Question.
What is the trigger for the disease?
Any asisstance would be grateful (and as soon as you can because it is urgent)
You have bitten off the BIG question. The gene is present from conception, but disease is apparent only 2/3 of the way through life. The trigger is not known for certain.
The gene is making an extra product that is somehow causing the disease. It is known that HAP1 (one of the gene products of the INIT 15 gene in HD) interacts with apoptane, a chemical involved inprogramed cell death. Another gene product also sticks too much to GAP DH, a mitochondiral membrane bound enzyme that is important for oxidative metabolisom, which is also impaired in HD.
Whatever the trigger is, it is not apparent until the disease is just about to appear clinically.
From Stephanie we have:
My name is Stephanie and I am doing a 16 page report on Huntings Chorea for Biology class. I have allready used your page for a lot of the stuff, and it has really helped. I do have one question though.
Who discovered Huntings Disease, and when was it discovered.
That is the only thing I can't find, and my report is due Monday! If you can help I would really appreciate it. Thanks, Stephanie
George Huntington, MD used to do rounds with his father on horseback, on Long Island in the 1800's. During a presentation that he made on Chorea. as a resident at the Cleveland Clinic, he mentioned an inherited disorder characterized by chorea, loss of cognition and clumsiness. He later publised these findings. This was the first mention of HD in the medical literature and it is why the disease bears his name.
From ImLuka@AOL.COM we have the following answers to her questions:
What unusual questions you have asked of both a scientific and a personal nature. I am most interested as to why you wish to know some of these answers.
Some food for thought:
Could you answer these few questions and return them to me very
quickly: 1. What age are you when the disease first affects you?
Average age of onset is 37, with a range from 2 years to 90+ years old. Average duration of disease is 19 +/- 10 years, with the general rule being that the first 2/3 of life are spent without HD and the last 1/3 with HD.
2. What are the signs?
Please read my page:
http://www.kumc.edu/instruction/medicine/neurology/Dubinsky.html and the rest of this page.
3. How does this affect your life style
Try my page that deals with disability:
http://www.kumc.edu/hospital/huntingtons/disability.html and the page that deals with behavioral issues: http://www.kumc.edu/hospital/huntingtons/behavior.html
4. How do people usually react to people with the disease?
In a wide variety of ways from calm acceptance and offers of help to shunning a person because they appear to be drunk.
5. How is the disease treated?
Currently there is no cure. Sympotamatic treatment can be given through the cautious use of medicaitons to treat some of the symptoms (e.g., depression, paranoia, choreaform movements that interefere with the ability to do everyday tasks) and through behavioral means.
6. What is your history with patients who have this disease?
Care of HD patients, those at risk and their families as part of the HD Clinic at the University of Kansas Medical Center.
7. What are your qualifications?
Try visiting my home page in our Department of Neurology: http://www.kumc.edu/instruction/medicine/neurology/Dubinsky.html
Please let me know why you needed this information and in what format your school report will be completed so that I may properly include you on my school report page.
From Arianna we have:
Dear Mr. Ummmm...(sorry, I don't know your name),
I am doing a report for my A.P Biology class on HD. This report is divided into 4 main sections. They are
A. The "normal" nervous system/neurological anatomy, pysiology, functioning, etc. State of "nondiseases", "nondisorder" organsim B. Affect(s) of disease on the "normal" state of organism C. Discussion of disease: Include, but not limited to, acquisition, prognosis, diagnosis, treatment, cure, etc....D. Interview: Actual or "compiled" interview of individuals with disease Conclusion If you could give me any information at all on any part of this report, I would greatly appreciate it. My current average in this class is a 64, so I have to do a good job on this report. Thanks. Arianna
You have a lot of work cut out for you.
First visit my site:
http://www.kumc.edu/hospital/huntingtons/ which is where you probably got my name. Visit many of the links, one of them should have one of the staging schemes listed.
To find a patient, try to contact a University Medical Center that has a HD clinic, present your case and ask them if you could observe a clinic and talk to some of their patients.
From Robyn on May 14,1997 we have:
Dear Dr. Dubinsky--
This is Robyn A. I e-mailed you a while back asking for info on Huntington's Disease and you asked me to reply with my grade!! Well first off let me thank you for the information you gave me--i used everything you told me and also used you as a reference!! I got 199/200 on the report -so i only missed one point and that was student evaluation, only one person of the whole class of 9 girls-on gave ed about that!! Thank you very much again--Yours, Robyn
From Catesby Holmes we have:
Hello. First of all, I would like to say that your page to help
with school reports (that would be the page for me) is great. That's a
wonderful idea and I got a lot of help from it, but I need a little more
on one of the questions. Could you tell me some more famous people with
huntingtons? Didn't a president have it? I fyou know of more than woodie
guthrie and you could tell me, i would appreciate it. Sincerely,
No US president has had Huntington's Disease.
From Katie Brown we have
Hi. I am a sophomore at Delaware Valley RHS in NJ and am doing
a project about Huntington's disese for biology. I am the "mother" of twin
daughter's suspected to have the disorder. I need to know whether it is
possible for one to inherit it or if both of them will if they are NOT
identical. Can you help me out?
Each child has a 50 % chance of inheriting anautosommal dominant disease like Huntington's disease form a parent. For fraternal (non-identical twins) the chance is 50% for each. For identical twins the chance is 50% for the pair, either they both will or they both will not. There are rare cases where identical appearing twins are actually dizygotic or fraternal twins.
Now the tough part. Each child has a 50 % chance, like each flip of a coin is a 50 % chance for heads or tails. If in your case your 'children' are fraternal twins, one having the gene does not mean that the other will not. Each of the fraternal twins would have a 50 % chance.
From email@example.com we have:
I am a sophmore in college and have a report to do. Which deals with the choose that a person that has a family history of HD in taking the text or not. I know the basic ethics and have enough information on the disease but I need more information on the affects that it would have on there future and ther plans especially on how to prepare for the onset of HD.
Examples of possible reactions to the genetic testing results: Gene positive: Good outcomes: prepare financially for the future use of long term care, estate planning, decisions about having children and providing for them,the use of selective fertilization techniques so that future children would not have HD. Being opne with their family about HD
Bad outcomes: depression, suicide, denial, loss of job or insurance due to gene status (before the diseae began) employment discrimination, isolation by their family and friends.
Good outcomes: family planning, employment decision, fiscal planning knowing that HD will not be a problem, being able to provide support to family members with HD, living their life knoeing thqat they will not get HD.
Bad outcomes: survivor guilt over the fact that their sibling or parent has HD and that they will survive and not get it, job discrimination and insurance discrimination because they had the test (not just the fact that they were gene negative).
These are but a few examples that I hope will help you with your report.
From A. Wade we have:
I was just reading your website and seeing as it is the most informative (that i can find anyway) i was wondering if you get send me some information about the exact process of testing for HD (like what processes they go through and all that!! i obviously don't know much about HD but need the info for my major project for biology (obviously on HD) Any other info would be greatly appreciated. Please send to: firstname.lastname@example.org Thank You
Symptomatic testing ios done thorugh a neurological examinationwhere the diagnosis can be made based upon typical clinical findings and an appropriate family history. Where the family history is ambiguous or absent (adopted patient) then confirmatory testing can be done.
Presymptomatic testing is done of adults who are at 50% risk (parent has/had HD) or rarely for an adult at 25% risk where their parent can not be tested (dead or estranged from the family) and the grandparent had HD. Presymptomatic testing involves: neurological examiantion to determine if clinical signs of HD are present educational session with a genetic counselor counseling sessions with a mental health professional who is knowledgable aboiut HD to help the person learn what they will do with their test results.
After that then their blood is drawn and sent to a laboratory who will look at the INIT 15 gene on the short armof chromosome 4 by two techniques, Western blot and Southern analyses to count the CAG repeats.
The result is disclosed to the person in person,never by phone or by mail.
I hope that this will help you on your project. Please let me know what grade we received.
And there is more:
A Wade wrote:
Thank You very much for your reply to my querry about HD, I gave
the information to my teacher and she said it was very good but that i
needed more detailed information on the Polymerease Chain Reaction technique
to detect HD presymtomatically. I tried looking up PCR on the internet
but could find nothing about it related to HD (but lots about detecting
other disease - pretty popular technique i guess). If you know anything
about this technique in relation to HD could you please send me some information.
Once again I am in great appreciation.
PCR is a technique used to amplify and then clone sequences of DNA. The technique is the same no matter which piece of DNA is used.
From Charisma De Castro, a very pleasent young lady in Victoria, Australia, we have:
My name is Charisma De Castro and I am writing a report on the screening processes used in genetic counselling for Huntington's disease, for my year 12 biology report.
I was wondering if you could answer the following questions for my project. I have taken note of other websites which have information on HD as well as having other resources obtained from the school library.
1./ What are some of the genetic techniques used when screening for HD ( in regards to DNA testing and presymptomatic testing)?
PCR with Southern Blot analysis for confimration
2./ What are the biological implications involved with some of the genetic techniques used in the screening processes?
3./ What are some of the issues related to testing for HD?
Most of the issues are ethical. The information from the testing of a person who is presymptomatic is critical information regarding their future. The gene results in essence will predict their future (regarding HD) with 100% certainty. Many may not want that type of information or be able to deal with that information in an appropriate manner.
This information is not shared without the person's consent in order to prevent possible problems with employment, life insurance, health insurance, etc.
I hope you will be able to assist me in compiling my report and look forward to your reply.
Thank you very much!
Charisma De Castro
Year 12 Biology Student
I hope that this information will be helpful on your report. Please let me know what your grade is.
Dear Dr. Dubinsky
Thank you for kindly answering my questions-- they have been very helpful.
I was wondering if you could further help me by explaining the specific genetic tecniques involved with PCR testing and Southern Blot analysis. The other web sites that I have visited have only been able to provide me with brief summaries of both techniques, with no in-depth explanations of such.
I greatly appreciate your time and help.
Charisma De Castro
Alas, I am a clinical neurologist and not a basic scientist. A
good college level biology textbook should have descriptions of PCR and
Southern blot techniques.
Date: Sun, 01 Feb 1998 18:48:07 +1100
From: Sonny de Castro
Towards the latter part of 1997, I contacted you for information regarding testing procedures for HD for my year 12 biology paper.
The information received contributed to an A+ paper!!
Thank you very much for your assistance!! I have now been accepted into Melbourne University to complete an undergraduate course in science.
Charisma De Castro
From Amy Herlihy, also of Australia, we have:
My name is Amy Herlihy. I am currently doing a research report on direct genetic testing for Huntington's disease as part of my senior year biology course. In actuality, i have just recently returned to Melbourne, Australia after spending three years in San Antonio. I was wondering, if you or anyone in your organisation had a spare moment,if it would be possible to e-mail me some information for my report. i am having difficulties in locating information on the exact laboratory methods and techniques/processes used in this testing. For example, is PCR one of the methods used in this testing? And if so, how is it used specifically in reference to HD. I would greatly appreciate any information you could send me, even concerning the old linkage testing or the moral implications of this newer direct testing. I hope to hear from you.
Yours Sincerely, Amy Herlihy
Yours is my second request from Oz in two days,the one yesterday was from a senior in Victoria.
PCR and southern blot analysis are used to look at the number of CAG repeats in the INIT 15 gene. An abnormally large number of repeats of the gene on one allele is diagnostic of HD.
In most testing, the initial analyais is by PCR with confirmation by Southern blot.
The moral implications are rather profound. The decisions that can be made based upnone's CAG analysis are adult decisions, items regarding life insurance, occupation choice, retirement, monetary decisions, deciding whether or not to have children. Since there is no treatment as of yet for HD, presymptomatic testing is only performed onadults who wish to know their gene status, have no clinical evidence of HD and are able to dealwith the results in a way that will not be harmful to themselves or to others.
Knowing your future can be devastating. The decision for gene testing can only be made by the person involved. The decision can not be forced by medical personal, family members, friends or the elgalsystem.
I hope that this answers your questions.
From Flifel@aol.com we have:
I'm doing a project for my advanced biology class. I need to know if Huntington's disease is caused by any of the following chromosome deformaties: non disjunction, deletion, translocation, or inversion. i would appreciate any help you could give me. My e-mail address is email@example.com.
HD is caused by an unstable trinucleotide repeat (or stutter). Please see:
firstname.lastname@example.org we have:
I am a college student and I am doing an ethical report for my biology class. My teacher said that we could do Huntington's disease, but I can't find anykind of ethical issues so far. Could you please help me? I would greatly apreciate it! Thank you. My e-mail address is email@example.com. Thanks again for your help!
Try these on for an ethical dilema:
Should children be tested for the HD gene even though no cure or treatment exists at this time for HD.
Should genetic testig be used as a screen for employment just like a drug screen? People with HD spend the first 2/3 of their lives before HD begins. They are productive people like everyine else. Should they be denied employment over what will develop many years in the future?
Should a woman who is pregnant have the fetus tested for HD if either she or the father is gene positive for HD? If the fetus is gene positive should she have an abortion?
These are just a few of the many ethical dilemas regarding HD.
From Schfanz@aol.com we have:
I am doing a short presentation on Huntington's Disease for my Contemporary Biology class. I would like some additional information on the higher rate of Huntington's Disease found in Venezuela. Any idea why? Can you direct me to further info? Also, I would like a list of well-known people affected by this disease. You mentioned Woodie Guthrie. Is there a place to find more info?
Thanks for all your assistance -
Woody Guthrie is the only famous person with HD that comes to mind.
The rate is higher in Venzuela because of intermarriage. The smaller a breeding population, the more likely it is for autosommal domminant traits or disease to be expressed.
From firstname.lastname@example.org we have:
dear Dr. Dubinsky
is the HD gene attached to sex chromosome? please e-mail me at email@example.com you
The HD gene, INIT15 is on the short arm of chromosome 4.
From firstname.lastname@example.org we have:
Hi, my name is Justin Deshotel and I'm a sophomore at Mamou High School in Mamou, Louisiana. I am preparing a research paper on Huntington's disease and have found your page very helpful. I do have one question though. I need to know is HD is more common to a certain racial/ethnic/or age group or is everybody at the same risk of contracting the disease. Thanks for the great page, keep it up.
HD is most common in people of European ancestry, which is most likely a representation of the founder effect. The highest incidence of HD is in the Lake Maricibo region of Venzuela, where the incidence is 7,000/100,000. In North America the incidence is about 30/100,000. InJapan, I am told the incidence is 3/100,000.
HD is reported in almost all ethnic and racial groups, though I do not know of any reported cases in aboriginies or African bush people.
From Justin Chastain who writes under the address of Donna Lambright
(email@example.com) we have:
Dear to whom this may concern,
I have been reading articles from the past and present and I ran across something that is boggling my mind. I am a junior in BioII, and I am doing a report on Huntington's Disease(Chorea) and I read that the medication that they are giving patients is a drug that stops the production of dopamine(Sp). Now dopamine is a hormone that is an intertransmitter for biosynthesis. Biosynthesis creates dopamine, which is a hormone that relaxes the muscles. Now I also read about Parkinson's Disease, which is similar to Huntington's, just different chromosome and different ending. Now, they give Parkinson's patients shoots of dopamine to stimulate the process to produce the hormone to stop trembling. Now my question is why give one the dopamine and deny the other of the dopamine, when the hormone should do the same in both cases? If the dopamine would stop the involuntary muscle contractions, when why deny it to patients with Huntington's when if you give it to them it might stop some of the trembling and make patients more comfortable for the time being.
Any answers you may be able to give would be helpful. Thank you for
Dopamine is a neurotransmitter with four or more different receptors in the brain. D1 and D2 receptors are concerned for movement and have opposite actions. D3,4 and possible D5 are involved with emotions and possibly with memory.
In PD there is insufficient production of dopamine. Dopamine replacement helps to treat the symptoms of PD.
In HD the spiney interneurons in the striatum (caudate nucleus and putament) degenerate and die. They are involved in the regulation of movements and help to suppress unwanted movements. In HD the remaining cells of the motor system allow too many movements to occur. Haloperidol blocks the action of dopamine and lessens the excessive (choreiform) movements.
Haloperidol can also worsen the symptoms of HD by causing increased problems with walking and trouble swallowing. It is a symptomatic treatment that can work for somepatients withHD at certainstages of their disease.
I hope that this answers your quesitons.
And as a follow-up from firstname.lastname@example.org (manish j surati) we have:
thank you for replying so quickly. I have another question. How is HD genetically abnormal, like does it have extra chromosomes. Thanx again!
There is a stutter, the CAG portion of the INIT 15 gene has estra DNA causing it to behave differnetly than the product of the INIT 15 gene if the CAG repeat length was normal.
From Lindsey Powell (email@example.com) we have
Dear...um..I don't know your name!!
I just surfed onto your school report web page about Huntington's Disease. I just wanted to thank you soooooooo much for all the useful information that you provided! I'm in the 8th grade, and my teacher assigned us to do a 6 page typed report on a genetic disorder, so I decided to do Huntington's Disease, because my grandmother recently died of it. (step-grandmother, actually.) She didn't have any children, but her sister has 6!! And each of those 6 children has at least 1 child! The oldest already is showing early symptoms. They don't really talk about it much. ANYWAY, I was just wondering if there was anything that is definitely a MUST to put on a research papaer. I've got the symptoms, history, fetal transplantation, everyday life.... Is there anything I've missed?
A must for your research paper is the genetics of HD, both explaining autosommal dominant inheritance and the unstable trinucleotid repeat that is the cause for the expansion of the HD allele (INIT 15).
Skip the fetal tranpslant surgery unless you are struggling to fill up space. Instead look around the net for information on porcine fetal tranpslants either microencapsulated or pre-treated to remove the FD4 marker and thus decrease the immune response by the host. That is where the interesting work intransplants for HD are being accomplished.
Good luck on your report.
From Sarah in Greely, Colorado, we have:
Date: Mon, 24 Nov 1997 08:35:34 +0000
From: Brian Edwards
Your information has ben a great help in writing my paper. I'd like to say thanks a lot and good luck.
Sarah from Greeley, Co
From Amanda at (firstname.lastname@example.org) we have:
Subject: Re: school report Hello-
My name is Amanda. I'm writing a report on Huntington's chorea. I am writing a brochure like you would find in a doctor's office. I have found a lot of information and I would just like to make sure it is correct. * It is inherited from chromosome #4 * It is a dominant gene * It affects the brain and the body * It causes you to have emotional problems and also clumsiness, speech disorder, chorea, depression, slurred speech, and more. * It is found through a genetic test * There is no known treatment at this time When I finish the brochure I will send it to you. Thanks for your time.
Amanda Best of luck.
From David at (ST_FRISBEE@SCECA.OHIO.GOV) we have:
Subject: Re: QUESTIONS ON HUNTINGTON'S DISEASE
Hi, my name is David frisbee from Tallmadge,Ohio. I am doing a biology project on Huntington's disease.I would like to know what the main trigger for the disease is? Who discovered Huntington's disease and why is it named what it is? What is the average age for Huntington's disease to set in at. What is the earliest age and the oldest age it has been known to set in at? Is it more common in one gender or another? And lastly,what,if any,are the warning signs of this disease.Please send me your responses as soon as possible. Thank you very much for your help!!
If you have read the pages of my site, most of your questions would have been answered already.
George Huntington first desribed the disease that now bears his name during a presentation of Chorea thathe gave as a reisdent in the 1800's.
Average age of onset of HD is 37 with a range of 2 to over 85 years. It is equally disrtributed for both genders.
There are no warning signs of the development of HD. Many times the initial symptoms are behavioral, e.g. trouble with frustration or anger, or depression, other times the initial symptom is clumsiness.
Good luck on your report.
From Kelli V. Pydynowski at (email@example.com) we have:
Subject: Re: Huntington's Disease
December 1, 1997
Dear Dr. Dubinsky.
My name is Kelli Pydynowski, and I am a student at University High School in Normal, IL. My Biology II class is doing project dealing with Huntington's Disease and I was wondering how the test is administered. I know DNA is extracted form a blood sample, but I don't know how? Do you also happen to know the name of this test? (the one developed specifically to test for HD?) If you have any information about this test, please e-mail me as soon as you can. Thank you very much for your time.
Kelli V. Pydynowski
The techniques used to look for an expansion of the INIT 15 region on chromosome 4 (the HD gene) are PCR and Southern blot analyses. Not being a basic scientist I can not reliably tell you how the DNA is extracted. One place to look is:
The Huntington's Disease Collaborative Research Group. A novel gene containing a trinucleotide repeat that is expanded and unstable on Hintington's disease chromosomes. Cell 1993:72:971-983.
Good luck on your report.
From Jenny Riddle at: JRFlute (JRFlute@aol.com), we have
Hi. My name is Jenny Riddle. I'm a 9th grader at Hamilton Southeastern High School in Fishers, Indiana. My Acc. Biology teacher wants my class to make a brochure for a genetic disease. My group picked Huntington's disease, and I was wondering if you could help us with some questions.
1. Is there any cure for HD?
Currently there is no cure. Symptomatic treatment is available for many of the symptoms of HD and drug trials are under way to find a cure for HD.
2. What are some warning signs that you may have the disease?
Earliest signs of onset may be behavioral problems, clumsiness, decline in job performance and excessive or fidgety movements.
3. Is there any way to prevent it?
HD can not be prevented. You have the gene at conception, though the disease will not be present until about 2/3 of the way through your life.
4. What happens when you have the disease? (What kind of care would
For this, you will need to read my site, esp. the behavior page.
I hope you can answer my questions. Please write me back ASAP,
because my brochure is due Wednesday, Dec. 16.
Thank you very much,
I wish you luck, because after I send this to you, I will be posting your questions and my answers on my web site for school reports, so that your teacher can see where your answers came from.
From Deborah Kohlhardt firstname.lastname@example.org we have:
Subject: Re: The effects of Alcohol on an HD patient
I have found your page not only helpful but interesting as well! I am working on a ficitous case study concerning an individual with HD who drinks a keg of beer every three to four days and refuses to take perscribed medication because he cannot drink while on the medication. I could not find information regarding the effects of alcohol and HD. Also, the ficitous family has placed their father/husband in a nursing home because they feel they can no longer care for him. What is the research available on this? Are there specific hospitals which could care best for him? Assistance for the family to help manage the disease?
Thank you and keep up the great work!
People with HD lose the ability to gait or control their emotions. This disinhibition is similar to what happens when people consume alcohol, so the problem can be greatly amplified in your case study. Besides there are quite severe long term health risks to the chronic consumption of alcohol, such as the development of neuropathy, myopahty, Wernicke-Korsdakoff's syndrome, midline cerebellar atrophy. liver cirrhosis and esophageal varices (dilated veins in the esophagous that can rupture, cauisng the person to bleed to death).
Some people with HD drink to help with a problem, such as excessive movements, or trouble sleeping. Medications could replace the alcohol with benefit for the person.
Often in this situation, placement in a skilled nursing facility or a supervised living arrangement where alcohol is not available is one of the better options.
From Nmvball17 (Nmvball17@aol.com) we have:
hello i am doing a report on huntington's disease. i have a few questions.
1. what happens in this disease
There is loss of the spiny interneurons in the basal ganglia. This leads to incoordination, choreiform (dancelike) movements and behavioral abnormalities.
2. what is the cause of it genetically speaking
Trinucleotide repeat on the short arm opf chromosome 4.
3. what is the current treatment
Only symptomatic treatment is available.
4. financial considerations
Disability, loss of insurance.
5. anything controversial information surrounding the disease
Prenatal genetic testing, human fetal mesencephalic transplants
6. what are the future considerations
porcine neurotransplants, medication to stop the neurodegeneration
7. who would one see for this condition
A neurologist or psychiatrist.
please respond as soon as possible... thank you so much... nmvball17
Remember, if you found my web page, your teacher can find my web page.
From Waters (email@example.com) we have:
Dear Mr Dubinsky,
I'm doing a school report on HD, and had 2 questions, 1. Is the HD gene dominant or recessive?
2. What part of the body does it affect, (biochemical pathway such as the brain, lungs) Does it destroy the cells, or what?
I'd appreciate it if you could get back to me before Tuesday, Jan 6th. Thanks again.
Here's my address: firstname.lastname@example.org
Nothing like leaving your report up to the last minute. If you had read the material on our site, by now you would know that the HD gene is a dominant gene and that the major area of destruction is in the basal ganaglia (caudate nucleus and putamen) of the brain, where the spiny interneurons are lost. The biochemical pathway towards destruction is being ardently studied in many laboratories as we speak.
Date: Mon, 05 Jan 1998 21:12:37 -0600
From: Waters (email@example.com)
Subject: Thank you
Dear Mr. Dubinsky:
I just want to thank you for taking the time to respond to my daughter's questions, and even do so within her timeframe! (It is still difficult to accept the egocentricity of a fourteen year old.) We really appreciate the fact that you make the time and effort to answer questions.
Karen Waters @ firstname.lastname@example.org
Date: Tue, 20 Jan 1998 16:18:42 -0600
Subject: Fw: thanks
Dear Mr Dubinsky.
Thank you for helping me with my report. Your web page was very
Thanks for responding so quickly.
From Mailliard (email@example.com) we have:
From: Dubinsky@kuhub.cc.ukans.edu (RDubinsky) Dear Dr. Dubinsky,
I am a sophmore at Maplewood High School in Pennsylvania and I am doing a 12 page newsletter for health class. One of the issues in my newsletter is Huntington's disease (chorea), and I would like to include if at all possible in my newsletter some 1-800 numbers or that people with this disease could call for help or some addresses that they could write to. I thank you for your time.
Please look at our page:
For an updated (2 weeks ago) listing of world wide HD resources. To make things easier, if you are using Netscape you can download this page as text and import what you need into your newsletter.
From KMH713 (KMH713@aol.com) we have:
I am doing a report on Huntingtons disease, and I wanted to know, can it be contasious? What are the symptoms and you give me some imput on the disease, how many people in the U.S. or around the world have huntingtons disease, and much more.
Thank you it would be greatly appreciated. KMH713
HD is inherited, it can only be passed on to one's children. To find out the symptoms please read my webpage which is where you found my Email address.
Approximately 25-30,000 people have HD in North America and 125,000 are at 50% risk for the development of HD.
From Stephanie RAMI (firstname.lastname@example.org) we have:
Hello Mr.. Dubinsky,
Hi, I am a freshman and I need to write a 3-4 page persuasive essay. I chose "Should children be tested for Huntingtons disease" I know the basics of the disease and the likelihood that a child will get it from a parent that has the disease, but I need some reasons for and against testing.The information I already know is that the disease occurs later on in life, and there is no cure. A person should make arrangements if they know they will get the disease since someone should be there with them during the later stages of the disease. I don't think that is enough information to make into 3 pages though. I will eventually have to take a side on the issue and write a persuasive essay, but the report is a long way off, and I have not yet chosen which side I will take. I would appreciate any help you are able to give on this subject.
I think that you will have no trouble filling 3-4 pages on this topic. One background source on genetic testing is the Science Museum's consensus page which has been used to conduct discussion rgearding genetic testing. Their URL is:
Points to consider:
For, Parent's standpoint:
The right to know for their child so that they canplan for their and their child's future. Ease of the worry over whether or not the child will develop HD. Control over their own and their child's life.
For, Child's viewpoint:
The right to know what their future will be, the right toplan out their future.
Con, Child's viewpoint:
Their fate is sealed, their right not to know has been taken away. In essence their future has been taken from them. Depression over a positive result, depression over a negative result manifested as survivor guilt because their sibling wil get the disease and they will not.
Con, Sibling's viewpoint:
A gene positive sibling will be treated differently than a gene negative sibling.
Con, parent's viewpoint:
The parent's now have to deal with the fact of HD in one of them and in their child.
From an ethical standpoint, the right not to know is just as important as the right to know.
Just because we can do something does not mean that we should do something.
Good luck on your paper.
Date: Thu, 08 Jan 1998 17:48:50 -0500 From: RAMI
Subject: Re: Hello
Thank you so much for all your help regarding my essay, I am sure your link and all your information will be very helpful to me. I also appreciate how quickly you were able to reply. Again, thanks so much, your page was very interesting to me, I've learned a lot about Huntington's disease.
Mon, 09 Feb 1998 21:43:34 -0500
From Malinda Roberts (email@example.com) we have:
Thank you for such a useful page. I enjoyed the extra-credit points that your page afforded me.
R. L. Roberts
p.s. I plan to be a geneticist when I am an adult. Just imagine what kind of impact that your work has on the future; easy and convenient access to great information for any kid with a computer.
From spacey (firstname.lastname@example.org) we have:
once again i'm doing another report, this time on HD. I have found that its on chromosome for and has repeating strings of C-A-G. But i dont really understand the "error". Is the reason i can find nothing about it because no one knows or is it that my teacher worded this badly? The report is due tomorrow and must be between 500 and 600 words... I only have 100 thus far and I was hoping that you could give me info on the "error" itself.
DNA is composed of double strands of four amino acids. Each group of 3 amino acids forms a triplet which is the basic component or word of the DNA code. The DNA blueprint is read by messenger RNA in a negative/positive fashion, just like in photography. The RNA then makes the protein, etc. based upon the code.
In HD the exon, or begining of the gene which is labeled INIT 15 for interesting transcriptase 15, on the short arm of chromosome 4 has too many triplet repeats of the sequence CAG. Normal is 29 or less, 39 or more is associated with HD. Because the CAG sequence is too long the matching RNA is too long and the product the gene is altered. How the latered protein or gene product causes HD is being investigated intensely with the hope of being able to block what is happening.
I think that this will give you a few hundred more words.
From James L. (email@example.com) we have:
I am a seventh grade student currently enrolled Menlo Middle School, in California. For Interim, we are studying the neurological system and the brain. For the Science project, I am teamed up with Honora Huntington (I'm not lying) and want to know a few more answers, if that possible.
1) Is the disease contagious in anyway? If so, how is it transferred from child to child? HD is genetically based. It can only be passed fromparent to child.
Try reading my site first. The URL is:
A HREF=" http://www.kumc.edu/hospital/huntingtons/"http://www.kumc.edu/hospital/huntingtons/
2) Where does the name come from?
George Huntington, MD who first described the disease which later bore his name.
3) Where is this diease located in the body? Does it affect any other
organs in different systems or anywhere else in the body?
HD affects the brain, though all cells with a nucleus will have the abnormal gene.
4) Are there ANY treaments for this particular diease or in generally,
ANY neurological disorder?
Symptomatic treatments are available but no curative treatment and nocurrent treatment that will slow or halt the progression. Most treatments for most medical conditions (e.g. hypertension) are symptomatic and not curative. Many neurological disorders have better symptomatic treatment than HD.
5) What lasting affect will this have on a person? (I.E. Is it fatal?)
Yes, it is fatal.
6) How is it caused, or is it only possible to inherit the diease
from the birthmother?
Please read the page:
A HREF=" http://www.kumc.edu/hospital/huntingtons/genetics.html"http://www.kumc.edu/hospital/huntingtons/genetics.html
Thanks reader, for reading this. If it is possible, could you
try to answer one or more questions as soon as possible. THank you very
From Peter Ahn (JungSun@aol.com) we have:
My name is Peter Ahn and I'm a sophomore at Bishop Ireton High School in Alexandria, Virginia. I like to ask you some questions on Huntington's Disease which will help me a lot for my biology project. What types of effects (physical, mental, and emotional) would be expected from this disease? What is the life span for a person who is affected with HD? What ways are there of dealing with this disease (therapy, drugs, diet, etc.)? Are there also any other interesting informations about this disease? Please reply soon.
Thanks a lot,
A lot of what you have asked can be found by reading my site. But here are a few pointers.
1) The effects of HD are in three areas: motoric or the abnormal movements and clumsiness, cognitive, specifically trouble with sequential tasks and working at a task in a confusing or distracting environment and behavioral. In the last area, some people with HD have problems with the gaiting of emotions. They can become upset or even violent, easily and with little provacation and then calm down and forget the incident rapidly.
2) In general, with adult onset cases of HD, the first two thirds of life are disease free,the last third is with HD. So if a person develops HD and they are 40,they will probably live another 20 years with HD. The statistics are the average age of onset is 37 years with a standard deviation of 19 years. The average duration is 17years with a standard deviation of 10 years.
3) Symptomatic treatment can be used, but there is no cure for HD. Adaptive devices and different therapies can help a person with HD to remain independent and to maintain a good quality of life.
Good luck on your paper. Remember, if you can find my site, so can your teacher.
From Kimberly (KLBRA@pwvsatt.attmail.com) we have:
Dr. Dubinsky, I have a few more questions I hope you can answer: 1. In what order, if any, do symptoms most generally appear (i.e., personality and/or cognition changes prior to evidence of motor disturbances)?
Onset symptoms vary greatly among patients and are not the same even for members of the same family.
2. Do we know what, specifically, causes the loss of cells in the brain?
Cell loss appears to be associated with cytoplasmic and nuclear accumulations of 'crud' that stain for the INIT 15 gene product huntingtin (note the -tin ending, this denotes one of th products of the gene (INIT 15) that causes HD).
3. What is the connection between the loss of cells and the defective
gene (i.e., is it thought that the defective gene CAUSES the loss of cells)?
4. Do we know why juvenile onset of HD happens in cases where the defective
gene is most often inherited from the father?
This is the genetic feature known as anticipation, where there is an expansion of the gene and the disease has an earlier onset with paternal inheritance.
5. In cases of juvenile onset, common symptoms include rigidity or muscle
stiffness and slowness. Is it possible for a child to show this symptom
but still not fully develop any other symptoms until adulthood?
Thank you again for your help!
Good luck on your report.
From Brandon (BAXTER17@aol.com) we have:
HELLO, MY NAME IS BRANDON TWING AND I AM A STUDENT AT MASCONOMET HIGH SCHOOL AND I AM ALSO WRITING A PAPER ON HD. I HOPE THAT YOU USE THIS LETTER IN YOUR WEB PAGE BECAUSE IT TELLS ABOUT MY STUGGLES WITH THE DESEASE. JUST A MONTH OR TWO AGO MY GRANDFATHER PASSED AWAY HE WAS 83 AND HAD BEEN SUFFERING WITH THIS UGLY DEASE FOR ALMOST HIS WHOLE LIFE. HE WOULD SPEND HIS WINTERS IN FLORIDA AND SUMMERS IN THE U.S. EVERYTIME WE WOULD GO TO VISIT HIM IT WOULD GET HARDER AND HARDER TO TALK AND SIT WITH HIM. HIS SPEECH WAS SO GONE THAT WE WOULD HAVE TO HAVE HIM REPEAT EVERYTHING HE SAID. AND TO WATCH HIM WE WOULD GET SO WORRIED THAT HE WOULD FALL OUT OF HIS SEAT. WE WOULD ALSO WONDER HOW HE COULD BEND AND FLEX HIM BODY PARTS THE WAY THAT HE DID. WELL AFTER MANY YEARS OF WATCHING THIS HE FINELY GAVE UP HIS FIGHT. NOW THAT HE IS GONE HIS WHOLE SIDE OF THE FAMILY IS GETTING TESTED FOR IT. IT IS SAID THAT ASTHE GENERATIONS GO ON THE KIDS WILL SHOW SIGNS AND SYMTOMS AT A YOUNGER AGE. WELL I AM 17 NOW AND I JUST CAN'T IMAGIN WHAT IS AROUND THE DOOR FOR ME.
Your story is a touching one. If HD is inherited through the father the age of onset tends to be earlier while if inherited through the mother, the age of onset is about the same. Each child of a person with HD has a 50% chance of inheriting the gene and eventually developing the disease. If your parent (I am not certain if it was your father's father or your mother's father who just passed away) does not have the gene, then you are not at risk to develop HD. If your parent does have the gene, your chance is 50 % of having the gene.
Look for someone to talk to, like a counselor at your High School or someone who works with a HD clinic in your area.
Thanks you for letter, and by the way, when you write in all capitals, it is the equivalent of yelling.
From Lindsay (KRC6022@aol.com) we have:
My name is Lindsay. I just had a question about Huntington's Disease. Are there any special organizations that have to do with this disease? Like...to help patients or to raise money or anything? Thanks!!! My e-mail address is Lindz00@AOL.com.
You can read all about the three organizations: the HDSA, the FCCHD and Hereditary Disease Foundation. Links to them may be found at the end of this page on my site:
From Lauren (firstname.lastname@example.org) we have:
Hi, my name is Lauren. I have to do a report on Huntington's Chorea, and I was wondering if you could help me. I have already used your web page a lot, and I thank you for that. The stuff that I need to know for my report is:
cause of disease, description of disease, who gets it, how does it affect the patient, treatment options, how is it transmitted, location of gene and or genotyp, and who discovered it.
I have already used your page, and it has helped me out a lot, but if you co8uld answer some of these, that would be a great help. The basic ones I have, but some of the harder ones I have been looking for and have not been able to find. Thank you very much.
HD is caused by a mutation of the INIT 15 gene on the short arm of chromosome 4. The gene was found by a team headed by Nancy Wexler, PhD and Dr. Guesella from Harvard Medical School. In the gene there is a repetition of the sequence CAG. This excessive repetition or stutter causes the product of the gene to be wrong and this somehow damages the caudate nucleus and putament of people with HD. How this happens is a hot area of research at this time.
Each offspring of a personwho has the HD gene has a 50% chance of inheriting the gene and getting HD. There is no carrier state. If a person who has the gene lives long enough, they will get HD.
Please look at the rest of this site for a description of how HD affects people.
Good luck on your report.
From Kimberly Braman (KLBRA@pwvsatt.attmail.com) we have:
Thank you so much for this site! I have found it extremely informative and useful. I am a college freshman, writing a paper on this disease. I've reviewed your comments and the literature but cannot find the information I am seeking. Can you please provide me with examples of the actual "causes" of death for a person afflicted with HD? I know that the disease "in itself" is not fatal, but that a person with HD will die from some complication thereof. I need examples of these complications (i.e., suicide, choking, etc.).
One other thing, could I please have your title at K.U.?
Thanks for your help!
The most common cause of death of a person with HD, like Alzheimer's, Parkinson's disease and cancer is aspiration pnuemonia. Usually people at the end of a neurodegenerative disease have difficulty in swallowing food,liquids and their own saliva, leading to asipiration.
Suicide is a rare cause of death of those with HD, but probably more common than in the rest of the population.
I am an associate professor in the Department of Neurology at the University of Kansas Medical Center. You can view a picture of me and read a short c.v. at: http://www.kumc.edu/instruction/medicine/neurology/Dubinsky.html
From Alison Dressler (Alibaba951@aol.com) we have:
Dear Mr. Dubinsky,
I was planning on emailing you with some questions about Huntington's disease, but then I read this page and it really helped! All my questions were already answered! Thank you very very much!
Thank you for your kind review of my site. If only everyone managed to read the material before asking their questions.
From Shawn (email@example.com) we have:
"Huntington's disease is inherited in an autosommal dominant fashion. Each child of an affected parent has a 50 % chance of inheriting the disease and is said to be at risk."
Just a comment on this statement although its not false this percent should be higher. If huntington's is a true autosommal dominant inhertor disease then you have to tell people that you were using one heterozygous huntington's dominant parent (Aa) and one recessive normal parent (aa) to get the outcome of 50% of the children acquiring the disease. There are also other possibilities, like say for instance still only one of the parents had huntingtons but was homozygous dominant (AA) then the outcome would be 100% of the offspring would acquire huntington's or carry the gene for huntington's disease even if the other parent was normal (aa). Also that when two people who had the disease but they were both heterozygous (Aa) then the children would have a 75% chance of having the gene for huntington's disease. Anyways if any of my information seems to be wrong then please write back, and im not trying to be a pessimist but the best case scenerio seemed to be mentioned here and not the whole scenerio.
I am doing a paper on huntingtons and found your web page usefull, thanks to the day and age when information of the world is at one's finger tips... Your response would be greatly apreciated ASAP. Im hoping to find as much as possible on Huntington's disease and know at this point in time that my knowledge of the disease is very small so please don't take offense to my e-mail, if its wrong in thinking.
Student of genetics
You are correct about the risk if a parent is homozygous for the HD gene instead of heterozygous. To have a homozygous parent you would have to be in an area where the incidence of HD is very high. That is rare, but reported in the Lake Maricibo region of Venzuela where the incidence of HD may be as high as 7,000/100,000 population, unlike the usual incidence in North Amercia of 2/100,000 population.
From Chris Whitted (firstname.lastname@example.org) we have:
I am a third year student at Ball State University in Indiana. I am currently taking an Honors course on Bioethics, in which we were assigned a term paper. The topic I chose was "Ought or ought not parents tell a 15-year-old child that a test shows the child to be a carrier of the Huntington gene?" While I haven't had a problem finding basic information on Huntington's (your site was a major help btw), I can't seem to find much on ethical implications. Personally, I take the stance that the parents should tell the child for a number of reasons (possilbe sexual activity, effects Huntington's could have on the child's plan for his or her life, awareness that a parent may develop the disease, etc.), but my instructor seems to want us to back our statements with citations from several (5) sources, primarily medical journals. I've found at least one in the pamphlet "Facing Huntington's Disease" and I was wondering if you could point me to any others, or had comments of your own.
Thank you for your time,
Your instructor has goofed with your assignment. Children are NOT tested for gene status, therefore the parents of a 15 year old would not the gene status of their child and not face the dilema of telling them. There is no carrier state. Either a person is gene postive of negative. If positive they will get HD if they live long enough. The only possile scenario where this could happen would be a couple that underwent fetal direct gene testing and then decided not to abor the fetus when they found out the results.
Any couple entering into fetal screening agrees before the testing starts to terminate the pregnancy if the fetus is gene positive. They are not forced to undergo the abortion, and there are two families who have chosen not to abort after finding out the positive gene status of their now child. The reason behind this is that the risk of chorionic villi sampling to obtain the tissue for direct gene testing is 3-5% for spontaneous abortion. A couple should not face that risk unless there is a strong need for the answer, such as termination in the case of a gene positive child. Would a couple face that risk just to know the gender of their child?
In the case where the couple decided not to abort the fetus een though it was gene positive the answer would most likely be disclosed years before age 15. The parent with HD would be symptomatic (average age of onset 37 years, range 2-89 years). With all of the emotional problems of HD the symptomatic parent would be likely to say "see, you are going to look just like me some day soon" or the unaffected spouse could say in teh heat of the moment ' you are going to be just like your other parent some day soon."
HD is an adult onset disorder. The decision to be tested is an adult decision, not that of a child. As you have learned from my site, the right not to know is as strong as the right to know. Once the answer is given, it can not be taken away. The decision made with the knowledge of gene status are adult decisions, having children, adopting children, career and finnancial choices. These are not the decisions of a 15 year old.
Enough of my pontificating, I sometimes get overly excited when faced with questions about the testing of children for HD.
If you keep your scenario, references to look for that would be of help have been written by Martha Nance, MD and Kimberly Quaid, Ph.D. You can do a medical literature search by Medline, for free, at :
and just follow the directions. You can also look in the journal Neurology in 1997 for a Practice Parameter on direct gene testing in HD.
Now for some fun. Try using my above arguements to tell you instructor that the scenario is flawed and that you want to try another one. The following were proposed as ethical dilemas by genetic cousnelors and are used as illustrative cases in bioethics courses/discussions.
1) Breast cancer (or you can use colon cancer). A person,with several sisters (or brothers and sisters) hase been found to be gene positive for BRCA-1 (or the autosommal dominat form of familial adenomatous polyposis which always leads to colon cancer) and is about to undergo a mastectomy (or colectomy). They do not want to inform their sisters (brothers and sisters) and dorbid you to do so, even tough if teh siblings know about the risk, they can be screened for cancer and avoid a fatal cancer, if they are treated early enough. Should the family be told or not?
2) Two dwarfs are married and the wife is pregnant. They want direct gene testing for the fetus for dwarfism. If the fetus is a dwarf (heterozygous), like them, they will have the child. If the fetus is homozygous, they will abort, since this is a fatal mutation. If the fetus does not have the gene for dwarfism, they will also abort, since the child will not be like them.The child would be of normal stature. Do you provide the counseling and the testing, knowing that a normal fetus may be aborted becuase it is not a dwarf?
3) A woman who is a carrier of Duchene's muscular dystrophy gene (sex linked) has had one son die from Duchene's and does not want to have another child die from this fomr of muscular dystrophy. She is pregant and wants direct gene testing. If it is a boy with the gene she will have an abortion. If it is a boy without the Duchene gene she will have the baby. If it is a girl (who can not get Duchene's because of the other X chromosome) who has the Duchene gene she will abort the fetus, so that she can not have a grandson who could have Duchene's. Do you provide the counseling and the testing?
These are fun dilemas to look at and work through.
Good luck with your project and let me know how it turns out.
From Hilary (Hillville1@aol.com) we have:
My name is Hilary and i'm a freshmen at Ridgefield High school. I had to do a pedigree relating to Huntington's. I read over some of the page and it really helped. It would help , though, a lot, if you could, or someone else, organize it by topic or something. I'm just looking for the genetics, and that was all mixed in. I don't want to seem ungrateful or anything---so thanks. It realy saved my assingment.
From Martha Charney (email@example.com) we have:
Hello Dr. Dubinsky,
I would just like to start off by saying that I am using my fiance's e-mail address to contact you on the subject of Huntington's disease. I am a medical technology student at UMDNJ-SHRP and need information on Huntington's. Each student in my class has been given a disease to research and I was given Huntinton's disease which I must do a presentation on in two months. It is required of me to present a fictitious case study of a patient exhibiting symptoms of Huntington's disease. I have found that type of information and how it is caused genetically. However, I need to try and include the following areas into my presentation: hematology, immunology, chemistry, microbiology and urinalysis. The types of questions I need to answer are such things as: Chem 7 results for a patient with Huntington's disease, CBC for a patient with Huntington's disease, if a patient is prone to bacterial infections, etc. I have been looking for this type of information and can not find it anywhere. Any information you can provide me with or if you can lead me in some direction will be greatly appreciated.
Routine laboratory tests as you list above are normal in HD.
People with HD are prone to aspiration pnuemonias towards the end of their disease, just like the elderly, those with cancer, Alzheimer's disease, stroke, etc.
Thank you for your quick response. If I have any other questions I will e-mail you again.
From Kristi Maxwell (firstname.lastname@example.org) we have:
i like you site b/c it gives you info that you need.it has been really useful for my research paper!i also thought it was neat how you could view others questions.that lets you know that you're not the only person wondering about the same things.like i have said,this page has helped bunches!!!
From Keallaboo3(Kellaboo3@aol.com) we have:
I know that this page was probably intended to help people coping with HUntington's disease, but I would like to thank you for providing an intelligent source of information for my project (due tommorow)
Most of the comments that I get are from people like yourself working on a school deadline.
I hope that you get a good grade on your report.
From Woolub (Woolub@aol.com) we have:
I'm an O.A.C Biology student and I'm doing an ISU (independent study unit) on Huntingtons and I would like to include a lot of visuals as well as writing in my project. If you have any suggestions for me it would be greatly appreciated. Thanks so much, Heidi. PS ----I think your page is great! My adress is email@example.com
For visuals you are welcome to use those from the genetics section of my site. You may also wish to visit the OMIM site and dowload the text for the INIT 15 gene. You can then insert the text into your report and highlight the CAG tiplet repeat.
From Mehhnaz Hassan (firstname.lastname@example.org) we have:
Dear Dr. Dubinsky
I am a college student and for my Biology class I need to write a paper about the ethical issues surrounding a person's decision to take a test to find out if they have the gene for the disease. Should the person take the test or not. I would appreciate if you could e-mail me back right away with the information.
It almost sounds as if you want me to write your paper for you.
The way to approach this is to look at the standpoint of the person involved and what are the possible good and bad outcomes.
neagtive results: good outcome they decide to hae children and not to worry about HD. bad outcome: survivor guilt because their sibling is gene positive and their parent has HD and they will die form HD while the person who was tested will not.
positive results: good outcome: they save money for long term care, they see Europe while they can and they decide to adopt children or to have preimplanation testing so that only a child without HD will be born. bad outcome: depression, suicide...
Other areas to consider in your paper would be the effects on employment.
More from Mehnaz Hassan (email@example.com):
Dear Dr. Dubinsky
I wrote to you earlier about my paper that I have to write about genetic testing for HD. So far I have found many things thanks to your comments. However, you did mention something about preimplanation testing so only kids without HD will be born. I tried to search for this everywhere but I can't find anything about it. I would really appreciate it if you could explain to me what the procedure is and all the rest of the details.
Thank-You once again
Preimplantation genetic testing has been used experimentaly for several different genetic diseases and is becoming clinically available.
First the woman undergoes hormonal stimulation to produce several eggs at one time. The eggs are harvested with a laproscope. In a laboratory the eggs are fertilized with the father's sperm. After conception the fertilized egg starts to divide. When it reaches the eight cell or blastosphere stage, one cell is removed from several of the blastospheres. The blastospheres are frozen and then the DNA is extracted from the cell and amplified using PCR. Then the DNA is examined for the disease, in this case the CAG explansion for HD. If the CAG repeat is normal then that blastosphere can be implamted (after thawing) into the mother where it can develop into a normal fetus. At the blastospher stage one cel can be removed without apparent future harm to the fetus.
Good luck on your report.
From Leia (Leia1357@aol.com) we have:
i would like some help concerning my report for anatomy & physiology. if you could please answer some of my questions about huntington's disease.
1) a general description of the disease and the causes of it
2) interesting points about the disease
3) facts and details concerning the disease
4) target group for the disease (examples: age, sex, ethnic group, geographic region)
5) research for future poosible applications-future studies
I'm sorry, but you are going to have to read my site and do the research for yourself. Feel free to copy right from my web site. After all, your teacher can find my site too.
From Sonia (Sonia1210@aol.com) we have:
is huntington's disease a sex-linked trait?
In answer to your questions, HD is not sex linked. Each child of a person who has the HD gene has a 50 % of inheriting the gene irregardless of their gender.
To find someone to interview about HD try signing onto the HD Listserver and posting your question, asking them to reply directly to your Email address. Instructions and a link to join the HD listserver can be found at:
Good luck on your project.
From LeahmKim (Leahmkim@aol.com) we have:
Dear Dr. Dubinsky,
I am currently doing a report on this disease and I was wondering if you know of any type of graphs or visaul aids that might be useful for my 5min. oral report in biology class. I am a sophmore in high school and I am having trouble finding anything visual on the internet. Any sort of chart, picture, or graph will do. Thank you for you time. Sincerely, LeahmKim@AOL.com
Visual aid requests have been quite common this Spring. You are welcome to use the graphics from my genetics page. If you go the OMIM site you can download the DNA sequence for the INIT 15 gene. Open the sequence in a word processing file and then highlight the CAG repeat. For a five minute talk, you should need no more than 3 or 4 visual aids.
Good luck. I have found a better idea, because it took too long to download your charts. I decided to use an overhead projector and just have facts about the disease. But thank you anyways, and thank you for your web site, it helped alot on my written report. Leah
More from Kellaboo3 (Kellaboo3@aol.com):
Subject: Re: Just a thank you
Actually, even though I doubt you still care, we were the only ones prepared in our entire class for the report, and my frazzeled, ticked-off science teacher was not in a particualrly lenient mood when she graded our uplifting (sarcasm) presentation on a deadly, incurable disease. Are they even trying to find a cure for this? Most of my class got very upset when they heard nothing could be done about it.
I'm sorry that you teacher did not appreciate your report. Work is currently underway in understanding the mechanism by which HD causes damage to the brain and how the damage can be stopped or reveresed. One medication study currently underway at our University and at 20 other sites, is the CARE-HD study. In this 30 month study, run by the Huntington Study Group at the University of Rochester, NY, people with early HD are treated with either Co-Enzyme Q-10 or Remacemdine in a two by two double blind placebo controlled study. The idea is to see if one or both of the medications can slow the rate of progresion of HD. If successful, then the medication may be tried inpeople who are gene positive but do not yet have HD.
Now for the exciting stuff which is jusy getting into the scientific journals and which is years away from the textbooks.
In HD, like many of the inherited neurodegenerative disease, thereis an expanded region of the gene that is significantly longer than the normal gene. The HD gene codes (makes) a protein that is too long, and which does not fold like a normal protein should. The expanded region of the protein huntingtin (the product of the INIT 15 gene that causes HD) sticks to other copies in what has been recently termed a polar zipper (think of two halves of a zipper being joined together). The polar zipper of huntingtin sits in the cytoplasm of the cell and is not removed by the usual house keeping mechanism of cells, tagging with ubiquitin. They form inclusions that gradually destroy the neurons.
Mary MacDonald, Ph.D. and Gilian Bates, Ph.D., both in London, reported this finding in a mouse model of HD last Fall. Similar inclusions were reported in the brains of patients with HD in 1979 by Tom Chase, M.D. at the NIH.
Those of us involved in the clinical aspects of HD hope for an early cure for HD. Besides a cure, mnay medications can be used to treat the symptoms of HD such as the choreiform movements, depression, anxiety, anger, and so on.
Please feel free to share this information with your class and your science teacher.
From Lilly Li (firstname.lastname@example.org) we have:
Dear Dr. Dubinsky:
My name is Lilly Li, I'm from Australia, and am currently studying in year 12. I've decided to do my Biology CAT 2 on "Prenatal Diagnosis of Huntington's Disease". I have visited your website on Huntington's Disease, and got a lot of information from it. But there are just a few areas that I need specific assisstance on. If possible, would you please kindly answer the following for me, or direct me to a source of information. I would be truly grateful if you could reply a.s.a.p. to my e-mail address. Thanks a million times!
1. What are the specific chromsomes, genes, alleles and proteins relevant to the practice?
2. How is the disease caused and how it is inherited?
3. What are the latest techniques used for the diagnosis, and the steps involved?
4. What is the function of HD's gene and what would happen if it is removed?
That's all. Thank you again for your precious time. yours sincerely,
I always enjoy getting requests from OZ, things are slow here now that most schools have closed for the summer. Some of your questions can be answered by more closely reading the site.
HD is inherited in a AD fashion. The diagnosis is made based upon clinical findings in a patient with a typical family history. In those without a family history, but who have typical findings, direct gene testing is used to confirm the diagnosis. The gene is the INIT 15 gene on the short arm of chromosome 4. In most people with HD one allele has an unstable trinucleotide (CAG) expansion while the other allele is normal (heterozygous).
The HD mutation is a gain of function disease, not a loss of function. If it was a loss of function the normal allele would take over and produce the proper gene product. If a knockout mouse model of HD the mice fetuses were stillborn. The CAG expansion causes the accumulation of the huntingtin (proper spelling for the gene product) in the nucleus and cytoplasm of the cell. The expanded area on the huntingtin sticks to other copies and forms a proteinaceous mass that can not be removed from the cell.
Prenatal diagnosis is performed when one parent is known to be HD gene positive. The3 chorionic villi is sampled. Using PCR technique the fetal DNA is amplified and the INIT 15 allele is examined for a CAG expansion. Prenatal testing is only performed when the couple would have an abortion if the fetus is gene positive. Otherwise, it is not worth the 3% chance of miscarriage from the chorionic villi sampling.
Good luck on your report.
And in follow-up we have:
Dear Dr. Dubinsky:
This is just a short note to say thank you for kindly answering my questions. I really didn't expect to get a reply so soon. I will have a closer look at the website again. And just when you think I won't bother you again, I'll probably e-mail you one more time as I get closer to finishing my CAT, if there is still anything unclear to me. I hope you wouldn't mind.
From Regina Lie (email@example.com) we have:
Hi! My name is Regina Lie and I'm from Australia. I attend Ipswich Girls' Grammar School and is currently in grade 10. I am currently working on my assignment which you might have guessed, on Huntington's Disease. I really need to know:
ÿ Is HD sex linked or not?
On which chromosome is it located?
short arm of chomosome 4
Does it effect particular groups or people?
it is more prevalent in those of European ancestry but has been described in almost all ethnic groups
What are the symptoms?
please read my site for a complete description
What are the current treatments?
symptomatic treatments are available for many of the features (e.g. excessive movements, rigidity, depression, anxiety, paranoia) but there are no treatments available that are curative or that can stop or slow progression
ÿ How is this inherited disease be passed from one generation to
Autosommal dominant inheritance from either parent to child
Thank you for your attention and I hope that you will answer my questions ASAP!!! Before 7 September, please! My e-mail address is Baddy_Girlie@usa. Thank You!!!
From Ross Cooper (firstname.lastname@example.org) we have:
I was just browsing on the net while ago as I have to do a major assignment on HD and how a person can be tested for it with PCR and southern blot analysis. I have found your site very helpfully and generally very informative. I have also downloaded some info off the page as well.
thanks very much for running the page
From Ashley Weltsch (email@example.com) we have:
Hi! My name is Ashley and I am doing a fictional court case for my sophmore Biology class and I was wondering if you help me out a bit. The case is about a guy who is applying for a job in a research lab and they find out that he has HD through genetic testing (he was adopted, not knowing family history). My class has divided up into two teams and we have to present our case, whether he should be hired or not. I am on the hiring side and I was hoping you give me some strong arguments for my case. I also have a few questions....Has anyone with the allele for HD ever NOT developed the disease? Are genetic tests ever wrong? About what would cost a company to provide insurance to a person with HD? If you could e-mail me with some info ASAP it would be greatly apprectiated!! Thank you!
This Spring the requests for help keep on getting better and better.
Insurance costs (actually what I pay for my employees when I budget a grant) is $2522 per year. The larger the company, the more even the pricing and the less likely they are to have trouble paying insurance for a new hire with a known health condition.
The person you are looking to hire is gene positive, he does not have HD, but he will develop it is he lives long enough. The average age of onset is 37 years with a range of 2 years to 80+ years. About 20% of people with 39 CAG repeats (the lowest limit of positive for HD) will die at an advanced age without developing HD.
Would your company react differently if the test was for Alzheimer's disease, colon cancer, or breast cancer?
Your Email address appears to be US, so the Americans with Disabilities Act (ADA) comes into play. Under the ADA you can not inquire whether or not a potential employee has a specific illness. You can ask if they think that they are physically and mentally able to do the job. Even in the obvious case of a woman who is visibly pregnant, an employer can not ask 'Are you going to come back to work after you deliver?'
Under the ADA employers should not be able to screen for genetically based disease unless there us definite evidence that the employee could come into contact with substances that would directly harm them because of their genetic make-up.
Your best argument is that your company was wrong to test for HD in that you broke the law. If he is qualified you should hire him. Did he give consent for the testing and has he been informed of the results? To disclose the results to him without adequate preparation and counseling could result in depression and possibly suicide. Your company is a great liability on the basis of this testing and your decision to hire/not to hire. You need to talk to your company's legal counsel. A letter needs to be placed in his file stating that he was tested for HD, which the company acknowledges was wrong and the results of the HD tests were destroyed since the company should not have access to an employees genetic information.
Good luck and let me know how the court case goes!
From Troy (firstname.lastname@example.org) we have:
Hiya, my names Troy, im in Australia and Im doing a major assignment on Huntingtons Disease for my last year in biology before i start Uiniversity, here goes....
I understand most of the project, but the one sticking point is how
Huntingtons Disease effects the DNA of a person.....we have to provide
diagrams and explain which parts of a DNA strand are effected. Also i need
info on Presymptomatic Diagnosis of HD. If you could e mail me back some
info or a site i can get this info it would be great.....could you please
mail me at
and not at the sender address, because i need to access this info from many places and this is the easiest place to send it to. Any info would be much appreciated,
Troy In Australia Ü
I am just back from a working holiday, so I hope that this is not to late to be of help.
DNA and HD.
As you know DNA codes for RNA which then make proteins (in this case) based upon the original DNA template. The shape of the protein is determined by how the adjacent amino acids in the final protein bend and fold in relation to each other. In the INIT 15 gene there is a region of trinucleotide repreats of the code CAG. Normally there are 29 or fewer repeats and the protein product huntingtin (note the lower case H and the tin not ton at the end) looks and behaves normally. In HD the CAG region of the INIT 15 gene is expanded to 39 or more repeats. The gene product huntingtin looks and acts differently. Resent research by Gillian Bates and others show that the expanded huntingtin does not fold as the normal protein should. Instead it tends to clump with similar copies of huntingtin into a protenaceous mass in the nucleus and cytoplasm of the neurons. Ubiquitin binds to the huntingtin mass but is unable to clear it from the cell. It is believed that this eventually leads to cell destruction.
This is done for people who are at a 50 % risk of developing HD (either one parent has HD or is gene positive). Rarely it is done for people who are at 25 % risk (e.g. grandparent had HD) when the parent is either deceased or estranged from the family so that their gene status can not be determined.
There are several steps to presymptomatic testing. The first is a neurological examination to see if the person has clincal evidence of HD. This is followed by a session with either a geneticist of genetic counselor so that the person understands the genetics of HD and the risk of HD to their siblings and offspring. Then there follows a minimum of two sessions with a psychologist or licensed counselor to explore how the person will use the information of their gene status. After the person has passed through all of these steps, then their blood is drawn and the test is performed. The test results should always be delivered in person, never by phone or mail. Follow-up is made by telephone one week and one month after disclosure and there is at least one follow-up counseling session after disclosure.
Good luck on your paper.
From Jocyln (J Jay <email@example.com) we have:
Hi! Your site and the links are really great! I'm a year 12 biology student in Melbourne doing a report on HD for biology. After reading some of the questions (and your answers) I was just wondering why a Southern blot is done after the PCR test. So far, from the resources I have read I have only come across PCR. Could you also tell me what the accuracy of the above test is, the cost, and what happens if the number of CAG repeats is in the 'indeterminate' range? I really appreciate the information you have put into this site,
Thanks, Jocyln :)
Dear Jocyln; Southern blot is performed for confirmation of the pcr and also in the cases of extremely large repeats which would read as normal by pcr.
From Leonard A. Bucaro JR. (firstname.lastname@example.org) we have:
Dear Dr. Dubinsky:
I am a Tully high school and of course I am a student. I am in 7th grade and I'm doing a report on HD. Now I think I have a good idea about the disease but maybe you can clarify a couple of things. Now my report is not just about the disease it has a secenario. Well here is my secenario. A fireman has been diagnosed with HD. The symptoms have just been starting to show up. He does not want to tell his employer because he fears he is going to be fired. Yet he only needs 2 more years before he can retire. The last time he went to a fire he was told to put it in reverse instead he went forward. This is a totolly open ended question so I have to make up my own questions to answer. Can you please give me any info that might be helpful.
This sounds like a fun scenario. It involves a person with early HD, the Americans with Disabilities Act (ADA) and public safety.
The competing interests are:
the firefighters desire to continue employment and his desire for privacy about his medical condition the Fire Dept.'s desire to have able firefighters who will make the proper decision in an emergency the public's desire to have safe firefighters on the jab.
HD is progressive, but slowly so. Average duration from onset to death is 19 years, so he should live the two years before retirement. HD does impair a person's ability to have insight into their limitations. Thus he may or may not be able to determine if he is safe enough to be a firefighter. The only other person/s who would be able to determine his fitness for duty would be other firefighters, but to ask them may violate his desire for privacy. People make mistakes. Everyone can mis-shift or make a wrong turn, esp. people without HD. Why does your high school buy a new care for driver's ed. every few years? Because it has been backed into one too many fences on the parking lot. Under the ADA an employer must make reasonable accommodations for an employee with an illness. Are there duties that this firefighter could perform despite his early HD? Could he fight fires, but not drive the fire truck? Could he perform an adminstrative/non-fire fighting role? Could he become an instructor?
The over-riding or compelling interest in this case is public safety. If he is unsafe to be a firefighter, he must tell his employer and be pulled from active duty as a firefighter. The safety of the public in general is a greater concern than that is this individual. In essence, this would be no different from the medical retirement/disability of a motorcycle officer who lost a lower leg in a traffic accident or a fire fighter with unstable angina (a precursor to a heart attack) that would prevent him from doing the physical activities required to fight fires, or no different from a physician who can no longer practice due to substance abuse.
Best of luck and let me know how the paper works out and what your grade is.
From Lim Chern Chuen (email@example.com) we have a frequent
I'm a year 12 student doing a report on the pre-symptomatic diagnosis of huntington's disease I'm writing about the testing for the HD gene by means of PCR and electrophoresis. My problem is I couldn't find much literature(after 1993) about the types of primers used, and if any restriction enzymes used in the process.Hope you can direct me to some links or other information.
Lim Chern Chuen
Your best bet would be to go to Medline (www.igm.nilm.gov) and do a search. My guess is that recent papers will refer to previous papers ~1993 and say that they used the primers mentioned in the 1993 articles.
From Caitlin T (firstname.lastname@example.org) we have:
To Dr Dubinsky,
I am a yr. 12 Biology student from Victoria, Australia and am writing a report concerning the genetic applications involved in testing for HD. For part of my report I need to discuss the biological implications of the test. This has really confused me because I thought the test only involved taking a blood sample from the individual wishing to be tested. Can you help me with the biological implications associated with genetic testing for HD? This would be greatly appreciated as my report is due in soon.
Thanking you in advance,
The implications are ethical and moral not biological. Any tissue sample which has nucleated cells can be used for DNA extraction. Even skin scrapings could be used. In the blood test it is actually the WBCs that are used for the DNA and not the RBCs.
The ethical/moral problems are discussed more thoroughly in our web site in the genetics sections.
From Nenevae (email@example.com) we have:
Dear Mr/Ms Dubinsky,
Hi, I'm Nenevae, and I'm studying year 12 Biology in Melbourne, Australia this year. I'm having trouble finding if the CAG trinucleotide repeat is located on a specific exon, and am desperately seeking your assistance. It would be fantastic if you could help!
contains the DNA sequence of INIT 15 in humans. The CAG repeat is in the first exon at the beginning of the page.
From Manas Khurana <firstname.lastname@example.org we have:
I am a year 10 student at Glen Waverley Secondary College in Australia. I am doing a science report on Hutingtons Chorea and i have all the information i need. But i have one problem. I am going to present my report to the class as a web page on the computer and i thought i would be good if i can have a video which shows someone who is suffering from HD. I have looked everyehere on the net but can't find any videos. If you know of any sites where i can download these videos i would really appreciate it if you could let me know as soon as possible!!! Once again Thanks and i hope to hear from you soon.
please excuse my delay as I had surgery on Sept. 2 and I am just barely back to reading Email today. I realize that this is probably too late but the only videotapes of people with HD that I know are not available directly from the Internet.
From Timeus Family email@example.com we have:
I am a sophomore at Cody High School in Cody, Wyoming. My health class has been assigned to different genetic disorders... and I have chosen the Huntington disease. I would just like to thank you for your wonderful internet sight it helped me tremendously for my oral report... don't worry I quoted all of your work. Oh and I must add your diagrams are great for visual learners like myself.
Thank you - and good luck with new research! Sincelry,
Alexian Timeus :)
Thank you for your kind review of my site.
From Yuri Bahti firstname.lastname@example.org we have:
My name is Yuri Bahti and I am researching HD as part of a web page project (to be posted at a later date)for my Molecular and Cellular Biology class at the Univeristy of Arizona. Here is my question: What is the current dogma concerning why there is a degeneration of neurons in regions of the basal ganglia? I heard someting to the effect that the CAGs(?) might be cutting off neuronal axons which might lead to apoptosis due to a lack of other cells telling them to 'stay alive'. Any ideas?
p.s. Great site! I may want to ask you about linking it to ours when we get to that pt.
The most recent concept is that the unstable CAG repeat on the INIT 15 gene leads to an elongated segment in the huntingtin (notice the spelling) protein. These elongated regions stick to each other as polar zipper. These large protein clumps while marked with ubiquitin for removal from the cell, are not removed and somehow lead to neuronal cell death. This may come about though errors in oxidative metabolism. There is an increase in lactate in the striatum of people with symptomatic HD, but not those who are gene positive but do not evidence the disease.
From Sandra Vargas Nunes email@example.com we have:
I'm doing a report for Medical College on the diagnosis of Huntington disease. Could you give me some information? My name is Luciana and I'm from Brazil. My e-mail is: firstname.lastname@example.org I'm looking forward for your answer
Please excuse the delay but I had surgery recently.
Return to the introduction page of Caring for People with Huntington's Disease
This home page is supported by the Department of Neurology at the Kansas University Medical Center and by the Huntington's disease support groups.
Suggestions and comments are welcome. Please mail them to me at: Dubinsky@kuhub.cc.ukans.edu