GOING FOR THE CURE
11th Annual Convention of the Huntington's Disease Society
of America
June 28-30, 1996
Minneapolis, Minnesota
Report by Mary Price
1. General Overview of the Conference
The Huntington's Disease Society of America (HDSA) is dedicated to
eradicating Huntington's Disease by promoting and supporting HD
research; to helping families cope with the problems presented by HD;
and to educating the public and professionals about Huntington's
Disease. This three-fold mission was evident throughout the conference
as over 500 attendees (including individuals with HD, those at risk,
caretakers and health care professionals) were offered over fifty
sessions that addressed a wide range of issues pertinent to HD. Those
of us fortunate enough to attend this conference came away with a
comforting and encouraging sense of belonging to a caring and
supportive community, one that is sensitive to the needs of HD
patients and families and one that is fully intent on doing all it can
do to find a treatment and cure for HD.
The conference started with an opening session on Friday morning (June
28th) where we heard from Mark Anderson (Health Aide to Senator Paul
We1lstone, Democrat, Minnesota) who described the legislative actions
now pending in the area of health care. Presentations by several HDSA
officers and representatives also provided a useful orientation to
both the Association and the Conference. Especially noteworthy was the
announcement that next year's conference will be hosted by Rochester
New York and will be held June 26-29, 1997.
A short closing ceremony was held on Sunday June 30th and in between
we were treated to a cocktail party on Friday evening (which included
a program by folksinger Charlie Maguire who sang Woody Guthrie songs);
this was followed on Saturday by an early morning "Go For The
Cure" fun run plus a mid-day luncheon and an evening banquet with
dancing; and a non-denominational service was held on Sunday morning
(where Carmen Leal-Pock's singing was truly inspirational). These
occasions provided ample opportunity for meeting others and for the
kind of informal one-on-one conversations that make these conferences
so worth while.
This report covers only a few of the conference sessions (primarily
those that I and my family attended). These included: HD 101 and 102
(basic information about HD), Current HD Research; and Testing for
HD. No attempt has been made to actually summarize the entire contents
of any given session; instead, selected highlights are presented which
reflect either new information not previously known to me or my family
-- or a new way of looking at existing information.
It should be noted that practically all of the speakers reminded their
audiences that the information being presented during the conference
is based on what is now known about HD (much of it surfacing just
during the past 2-3 years since the gene was discovered) and that as
new developments are reported, new theories, facts and conclusions
will very likely emerge.
2. HD Basics 101
The speaker for this tutorial was Dr. Martha A. Nance, MD. Starting
out on an encouraging note, she observed that since 1991 there have
been over 400 research papers on HD (which is indicative of the
growing attention being given to this neurological disease).
Diagnosis.
A diagnosis of HD is determined by measuring the
number of CAG repeats in the Huntington gene. Based on the
experiences of the past few years, the "normal" range can be
considered to be between 10 and 34 or 35 repeats (with 17 being the
most common); and the range of repeats associated with the development
of HD can be considered to be 37/38/39 and above -- with a gray area
between 34/35 and 37/38/39 where the evidence is inconclusive and
where there is overlap between the normal zone and the HD zone.
However, these observations are based on the limited experience of the
past three years (since the gene was discovered) -- and the medical
profession is still learning and still refining these diagnostic
interpretations. It can be stated with a fair amount of reliability
that no one has been reported with HD who has less than 34 or 35
repeats. But Dr. Nance noted that the current issue of the American
Journal of Human Genetics carries an article which suggests that there
is no indication of HD development with 38-39 repeats. At the same
time she reported on two patients with 37 repeats: one who has HD at
the age of 45 and one who is showing no signs of HD at the age of 77.
More experience will certainly help to resolve this particular issue.
With regard to concerns about the gray area, two issues were noted:
- There are two different ways to do the gene test: some
laboratories isolate only the CAG repeats; other laboratories isolate
both CAG repeats and CCG repeats (which are located right next to the
CAG repeats on the 4th chromosome). The second method is easier to
perform but can result in a slightly higher count. The differences
between the two methods are generally irrelevant in those cases where
the numbers are clearly in either the normal or HD ranges. However,
these differences can be more significant if a count occurs in the
gray area (in which case, it is advisable to find out from the
laboratory which type of test was performed).
- Two properties are acquired by the CAG repeats when there are too
many of them: first, they can cause Huntington's Disease; second, as
the repeat number goes up, it becomes unstable, allowing for a greater
likelihood that the number of repeats will change as the gene is
passed from generation to generation. According to this view, an
individual with a count in the gray area who does not have HD could
pass on a higher repeat count (because of this instability) which
could result in a son or daughter with a CAG repeat in the HD range.
This phenomenon may help account for those instances of HD that occur
suddenly in families with no known history of the disease.
Symptoms.
- The dementia that accompanies HD does not appear to be the same as that
which occurs with Alzheimer's. With Alzheimer's, that part of the brain
which actually stores memory is destroyed. With HD, the actual memory is
apparently not destroyed in the same way; instead, it is the neural pathways
to the memory that seem to be affected. Therefore, HD patients usually
retain the ability to recognize family and friends.
- With HD, there is often not so much a personality change as an evolving
exaggeration of life-long behavior/personality characteristics.
- Weight loss occurs with practically all patients, which means
that attention to nutrition and keeping up the patient's weight are
important even early in the disease. (This prompted a variation on
the good news/bad news jokes:
"the bad news is that you have HD; the good news is that you can
throw away your diet books")
Pathology.
With HD, loss of cells in that part of the brain
called the caudate nucleus occurs. Current thinking indicates that
this loss probably occurs as a result of cell death when the
Huntington gene binds with a protein -- which results in the cell
acquiring a new and harmful function. Dr. Nance demonstrated this
theory very vividly using an ax handle as the Huntington gene and an
ax blade as the protein. Individually, these are harmless pieces of
material; but binding them together produces a potentially
life-threatening weapon.
Treatment.
- Some doctors discourage the use of drugs for controlling movements
early on, because dealing with the early movements is almost
considered to be a cosmetic issue. Instead, they wait for later
stages when the movements become severe enough to impair function.
- There are currently no pills or cures for the dementia; however, there are
many medications available to treat behavior disorders that accompany HD.
3. HD Basics 102/Tour of the Brain
Dr. Jane Paulson, MD was the facilitator for this session and she
began with a summary of the triad of symptoms that accompany HD:
motor, cognition and emotional.
- With HD, there is impaired speech expression, but language
comprehension remains intact.
- With HD, there is impaired learning, but recognition memory
remains intact.
- Memory and language disappear in Alzheimer's, but not with HD
(it just takes longer than usual to retrieve the memory); however,
motor memory remains intact with Alzheimer's but not with HD.
- With HD there are impaired "executive functions." This
includes: impaired decision-making abilities; organizational problems;
regulating problems (that is difficulties with temper control; and
problems with initiating activities -- which can often be manifested
by an appearance of laziness); and awareness problems (such as a
denial of deficiencies; unintentional non-compliance; etc.) While
these symptoms are social/behavioral in nature, their underlying cause
appears to be organic -- due to damage to the caudate portion of the
brain.
In reviewing the major parts of the brain (the frontal lobe, cerebral
cortex, parietal lobe, cerebellum, etc.) it was noted that the caudate
is the part most vulnerable to damage in HD. (However, it can be
postulated that something is also going on in other parts since
post-mortem examinations seem to reveal that the brains of HD patients
tend to shrink and weigh less than non-HD individuals). The caudate
runs through the entire brain, and as HD progresses, the caudate is
gradually destroyed. Messages and activity between and among the
frontal lobe and other parts of the brain pass through the caudate;
without the caudate, the pathways for these messages no longer
function properly. In other words, the part of the brain that stores
information appears to remain fairly intact -- while the pathways
via the caudate are what is washed out by HD. The caudate acts as a
filter and as a gate-keeper for the brain, helping to regulate and
organize actions. HD damage to the caudate leads, among other things,
to the impaired executive functions described above.
4. Update on Current Research
With Dr. Nance as moderator, a panel of four individuals provided an
overview of new developments in HD research: Dr. Jane Paulson,
Dr. Walter Low, Dr. Matthias Kurth and Dr. Nancy Wexler.
Representing the Huntington Study Group, Dr. Paulson reported that
current efforts are focusing on three areas:
- Providing symptomatic relief for those with the disease;
- Protecting nerve cells (including: blocking the effects of excitotoxins;
bolstering cell energy production; and scavenging free radicals)
- Replacing dead cells with new cells (including fetal tissue transplants)
She also summarized some of the recent achievements of HDSA:
- Formulation of the "Unified Huntington's Disease Rating
Scale" which all investigators use to judge changes in behavior,
movement, function, etc. Use of this scale helps researchers measure
the efficacy of experimental drugs in a standardized fashion.
- The first multi-center clinical trial for HD which evaluated the
benefits of "OPC 14117" on 64 subjects for 20 weeks. OPC
14117 is similar to high dosage vitamin E but it is able to pass
through the blood/brain barrier in the brain much more effectively
than regular vitamin E. The trials have been successfully completed
and the data are now being analyzed.
- New clinical trials are being planned for: Co-enzymne Q (which is
believed to help in energy metabolism); Remacemide (which may help
protect neurons against excitotoxins); and Riluzole (which attacks
free radicals and is already being used with ALS patients).
Dr. Nancy Wexler reported with great enthusiasm on a new $10 million
collaborative effort between Regeneron Pharmaceuticals and Medtronic,
Inc. to develop a potential treatment for HD involving growth factors
which might help protect brain cells from HD damage. The particular
growth factor being targeted is called CNTF, and the experimental work
involves formulating a pump that would be able to get CNTF directly
into the appropriate part of the brain where cell protection is
needed. As envisioned, the pump could be similar to a pacemaker, and
could be worn externally or perhaps implanted internally. Several
different groups have been experimenting with animal models, and there
should be considerable news about these developments during the next
year.
Dr. Walter Low and Dr. Matthias Kurth each reported on experimental
work with fetal tissue transplants. Based on the experiments so far,
it would seem that animal models work fairly well and that human
experiments are encouraging. Addressing in particular the experiments
at Good Samaritan Hospital in Los Angeles, Dr. Kurth reported that the
progress of the current three patients will continue to be studied
-- and that five more transplants will be undertaken, with careful
attention to pre-op observations and post-op follow-through.
It was noted that the following areas are candidates for future research:
- Predicting the age of onset (based on what is now known, the
number of CAG repeats apparently plays some role -- but other
factors certainly enter into the picture as well).
- Research on the gray area of CAG repeats (especially since new
mutations or what have been termed spontaneous occurrences are not as
rare as once thought and may be in part a function of gray area
repeats).
5. To Test or Not to Test
With Dr. Nance as facilitator, the following opinions or observations
were solicited from the audience regarding the highly personal issue
of whether to be tested or not:
- "I just wanted to know!"
- "As long as you're not tested, you have open-ended
uncertainty -- and I'm comfortable with that ambiguity."
- "As long as you're not tested, you always have the option of
being tested; but once you have been tested, you've lost your
options."
- "By being tested, you reach a certain measure of closure
-- and you can better prepare for what may be happening in the
future."
- "Even with the positive test result, you still have a lot of
unknowns, like age of onset and what HD will actually be like for
you."
- Insurance concerns are common (especially the impact a positive
test result might have on future abilities to get insurance).
Regarding the actual gene test, the process usually follows the
following steps:
- blood is drawn from the patients;
- then the white blood cells (carrying the DNA, which contains about 100,000
genes) are separated from the sample;
- then using chemicals that recognize certain sequences of letters, the
section of DNA that contains the CAG repeat is isolated;
- then, another chemical (Taq polymerase) is mixed with the CAG
portion of the DNA which, upon rapid heating and cooling, causes that
portion to multiply -- thereby providing enough volume to permit
visual inspection;
- then this enlarged portion of CAG repeats is put on top of some
jello-type material in a sieve; as water is poured through it, the
smaller genes (the ones with fewer repeats) pass through and go lower
while the larger genes (the ones with more repeats) get stuck earlier
in the process and remain higher up;
- from experience, one can associate repeat numbers (that is, 17,
24, 35, 42, etc.) with the relative vertical locations of the genes in
this process. Everyone will have two counts (one from each parent)
and only one has to be in the HD zone to be at risk for the disease.
What to look for when selecting a testing site
- Personnel who know something about genetics -- and more
precisely, personnel who know something about HD (and who are more
likely to have access to current information about HD);
- Ability to provide genetic counseling;
- Awareness of not only the technical issues of the testing process but also
the ramifications for the larger picture of the entire family;
- Some involvement or association with a physician who knows HD
HDSA can provide a list of testing centers. Cost for the test can
range from $500 to $1200. And the elapsed time from the beginning of
the testing process to getting the results can range from 3 weeks to 3
months (which includes counseling time). The actual time required for
the laboratory procedures is 2-4 weeks.
Converted to HTML by Renette Davis with permission from the author, Mary Price
[Note from the author: This report reflects the hand-written notes of
a lay person with an interest in HD. If it contains any
mis-interpretations or mis-information, please let me know and
corrections can be made. These should be sent to Renette Davis at the
address below. Mary Price -- Falls Church, VA]
Send comments to Renette Davis by clicking here.
Last updated: Dec. 1, 2010