Numerous questions about Huntington's Disease

April 24, 2012 1:48 PM

Multiple questions about Huntington's Disease... I'm researching a story that has a pregnant woman with Huntington's Disease. I've watched a bunch of videos on Youtube and read various sites but have not found answers to specific questions I have.

1. Wikipedia: "The most characteristic initial physical symptoms are jerky, random, and uncontrollable movements...These minor motor abnormalities usually precede more obvious signs of motor dysfunction by at least three years." Can these early symptoms be inconsistent? For instance, is it possible a person who has trouble walking one day can be fine the next or once a symptom reveals itself for the first time, is it permanent and escalating?

Specifically, is it possible that someone who experiences a "minor motor abnormality" today could appear "normal" to an outside observer tomorrow.

2. My question regarding this is probably ridiculous but I'm not in the USA (though my protagonist is), so I'm gonna ask it anyway. Wikipedia says, "Prenatal testing is performed on the understanding that if the fetus is found to carry an expanded HTT gene (or, in exclusion testing, found to be at 'high risk'), the pregnancy will be terminated." I'm not sure I understand this. Certainly a positive result does not insist upon abortion, does it? It is the woman's choice regardless of the test results, yes?

3. "Seizures are also a common symptom of [juvenile] HD." What about non-juvenile HD? Can seizures happen then as well? Can a seizure be an early or even first symptom or someone who is not a juvenile? (My character is 25).

4. Is, or can, stress be a factor in the appearance of symptoms, the way it can be for someone, for instance, who stammers?

5. Is there an anecdote about the illness that you wish to share that is outside of the scope of my questions? Memails welcome if you don't want to share on the green.

Thank you.

posted by You Should See the Other Guy to health & fitness (12 answers total)

hey, #2 real quick - it's always (supposed to be) the woman's choice. well....we'll see for how long in this climate anyway, i guess.

however, there can be a lot of coercion (in all directions): some doctors will, really shittily, insist to a woman that they will only do a genetic test pre-natally if the woman agrees that she will absolutely terminate if there's any abnormality found. this is clearly against all practice guidelines, but, yeah.
posted by circle_b at 2:05 PM on April 24, 2012

The people I've known with Huntington's had very consistent symptoms. That is, they might be able to force themselves to stop moving for a few seconds but their bodies were always trying to move. You do get good days and bad days though, as with most neuro diseases, so early on this might look like being completely normal some days? People tend to get referred to me fairly late on.

The people I have known with Huntington's did not also have seizures, but of course that doesn't mean they don't happen.

I'm not sure how far you will get comparing huntington's to a stammer. While both surely have genetic and environmental factors contributing, the balance is very, very different. Having said that I have definitely worked with people who have completely organic speech disorders which became worse under stress. That may be because stress tends to make everyone speak a little faster and maybe not phrase things so well, and that might be more noticeable in someone who already has some difficulties.
posted by kadia_a at 2:30 PM on April 24, 2012

What kadia_a said, and, additionally:

I think you'll get a lot of the information you need from the Huntington's Disease Society of America website, especially regarding symptoms and the ethics of prenatal testing, etc. The HDSA is incredibly important in the HD community and hospitals that test/treat/counsel patients with HD generally follow the counseling guidelines established by the HDSA or risk being blacklisted (so I hear).

As far as I'm aware, no, termination in the case of positive results is not a pre-requisite for prenatal testing. The issue involves revealing the HD status of the mother indirectly, if that is not already known, and since knowing one's own HD status has such huge implications for yourself and your entire family, this is often a major concern in prenatal genetic counseling. (For example, it's not entirely unheard of for suicide to be the result of a positive genetic diagnosis of HD in general, so...)

Seizures are extremely uncommon in adult patients with HD, and I wouldn't expect it to be the first symptom in a 25 year old. If a 25 year old showed up with seizures, unless they clearly had chorea or the other symptoms, or an abnormal MRI, Huntington's wouldn't even be #100 on my list of possible causes of that seizure. :)

Juvenile HD, which is extremely rare and has onset before the age of 18, presents more with rigidity, seizures, and early psychiatric features than the characteristic chorea (the "dance-like" jerking and uncontrollable movements). But the more generations you have of HD, the earlier that later generations present with HD, given the nature of the genetic abnormality.

As I recall, the uncontrollable movements aren't particularly worsened by stress or concentration. They simply tend to make things like dressing oneself (buttons) or feeding oneself increasingly impossible over time, as well as burning off so many calories through constant motion that the people tend to be pretty skinny. Early on, it's not so much "stop-start, normal one day, abnormal the next" so much as "subtle and easy to ignore", especially if you're a layperson or not suspicious or not watching closely.

I've seen a handful of people with this sad disease, including a few children, so I guess if you have more questions, feel free to memail me!
posted by vetala at 2:50 PM on April 24, 2012

Can these early symptoms be inconsistent? For instance, is it possible a person who has trouble walking one day can be fine the next or once a symptom reveals itself for the first time, is it permanent and escalating?

Yes on all counts. The early symptoms are very subtle, and the fade-in to empirical, measurable physical symptoms can be decade-long (or more). Some people never develop significant physical symptoms.

Once a person develops physical symptoms, however, the disease is progressive, and (while each individual day might be better or worse) tends only to get worse.

2. My question regarding this is probably ridiculous but I'm not in the USA (though my protagonist is), so I'm gonna ask it anyway. Wikipedia says, "Prenatal testing is performed on the understanding that if the fetus is found to carry an expanded HTT gene (or, in exclusion testing, found to be at 'high risk'), the pregnancy will be terminated." I'm not sure I understand this. Certainly a positive result does not insist upon abortion, does it? It is the woman's choice regardless of the test results, yes?

Abortion is not mandatory. In fact, most testing centers in the U.S. refuse to test fetuses on the grounds that that person has the right not to know if the parent decides to bring the person to term (though there's a subtext of wanting to prevent voluntary abortions in a lot of places). Most interventions are done on the level of the parent (testing pre-conception) or using IVF (to implant only non-HD embryos).

3. "Seizures are also a common symptom of [juvenile] HD." What about non-juvenile HD? Can seizures happen then as well? Can a seizure be an early or even first symptom or someone who is not a juvenile? (My character is 25).

I am not familiar with this as a symptom of adult-onset HD.

4. Is, or can, stress be a factor in the appearance of symptoms, the way it can be for someone, for instance, who stammers?

Again, yes on two counts: it can make the symptoms work on a day-by-day level, but it can also apparently cause earlier onset (as can other factors, like diet, exercise, and caffeine consumption).

5. Is there an anecdote about the illness that you wish to share that is outside of the scope of my questions? Memails welcome if you don't want to share on the green.

No, but you (and anyone else who ever reads this) is welcome to MeMail me if you're like to talk more. The disease runs in my family though I've now had the gene test and am not a carrier. This was my anonymous AskMe from when I was still at risk.

I've also written an article on treatments of Huntington's Disease in science fiction that might have sources you'd find helpful. MeMail me and I can send you a copy.
posted by gerryblog at 2:51 PM on April 24, 2012

1. Trouble walking is not an early symptom. People are more likely to first develop minor movements of the face/limbs, which can be very subtle and certainly appear and disappear. HD can also present with a mood disorder (depression and anxiety are very common, even long before the motor effects) or a psychiatric illness (e.g. schizophrenia). You can find more info here.
2. Two reasons for this. First, the prenatal test (CVS or amnio) is invasive and carries a risk of miscarriage, so people who wouldn't terminate an affected fetus usually wouldn't run the risk of miscarriage. Second, doing a test in pregnancy and then not terminating is in effect a predictive test on a child, thereby taking from them the choice of whether to have the test in adulthood. It is generally frowned upon to do predictive tests in children, for adult-onset conditions, unless a preventative treatment is available.
3. Seizures aren't common in adults.
4. Stress can definitely be a factor. In fact there are many cases of at-risk people presenting with symptoms and then having a negative test. Amazing what the mind can do to the body.
5. Nope, but good luck with your story and with raising awareness.
posted by superfish at 2:55 PM on April 24, 2012

This is a good resource for information about the juvenile form of HD, as it often presents quite differently to the adult onset.

Seizures can occur in adult-onset HD, but tend to be fairly rare and usually occur toward the very end of the disease course.

Speech problems are more likely to sound like slurred (dysarthria) or too quiet speech because of problems with having adequate breath support.

Stress and fatigue can make symptoms look worse, but I don't know that you would have a noticible symptom on one day, and totally absent another. Maybe early in the disease when it just seems like people are "too restless" or clumsier than normal you might see that wax and wane, but they usually don't have frank choreoform movements then.

Here is another resource about adult onset HD that touches on some of these issues.
posted by goggie at 2:55 PM on April 24, 2012

I wanted to clarify regarding the sentence you asked about with regard to genetic testing.

"Prenatal testing is performed on the understanding that if the fetus is found to carry an expanded HTT gene (or, in exclusion testing, found to be at 'high risk'), the pregnancy will be terminated."

The reason this is worded this way is because medical testing is generally not recommended just to determine a diagnosis if the diagnosis would not change the treatment or course of the disease. If we don't need to know the answer, we don't go looking for it. Typically, this is because it is wasteful to spend money on unnecessary diagnostic testing, and because doing unnecessary testing yields higher numbers of false positive tests. However, in this particular case, there is another important reason not to test for Huntington's disease if the mother would not seek an abortion if the test were positive - the test itself can be harmful to the fetus.

Prenatal testing for Huntington's disease involves either chorionic villus sampling or amniocentesis. Either one of these procedures is invasive (involves putting instruments into the uterus to take a tissue sample) and carries a risk of causing miscarriage or other complications. So in this case, it is particularly important not to do a test "just to find out the answer", and only to do it if a positive test result is going to change the decision making process.
posted by treehorn+bunny at 3:50 PM on April 24, 2012

Right, and it's not like early detection of Huntington's makes it any more treatable. If you have the gene, there's not really anything you can do about it besides deciding not to have children (or, as vetala points out, suicide). Since these are not decisions fetuses or babies or small children have to make, or decisions parents get to make for their children, no one *needs* to know whether a fetus is going to get Huntington's or not, unless the parents are planning on terminating the pregnancy.

But still, it would be the mother's decision - certainly I can imagine a woman getting the testing done thinking that she would abort if it came back positive, and then changing her mind.
posted by mskyle at 4:12 PM on April 24, 2012

I know this is not exactly what you're asking but I thought you might find it useful; I've been familiar with HD for years as a neuroscientist and have only recently learned about the impairment in recognizing disgust.

http://en.wikipedia.org/wiki/Disgust#Huntington.27s_disease
posted by Tandem Affinity at 4:15 PM on April 24, 2012

Agreeing with Superfish and mskyle that some couples undergo prenatal testing stating termination of pregnancy will be an option for them but then do not terminate if the fetus is found to be affected. Why do they change their minds? Turnaround time for prenatal testing of HD in the USA is usually 2-4+ wks for CVS vs 4-6+ wks for amnio (insert technical explanation here). So amnio at 15-16 wks has results back approx 20 wks gestation-a very different position both psychologically in the pregnancy and logistically in obtaining abortion services, especially for those who are not able to travel if services are not available locally. I am familiar with couples who've aborted prior to testing due to TAT/termination issues that they did not know of prior to achieving pregnancy. IVF/PGD has a been a boon to these couples. Preconceptual genetic counseling would have helped even more.

And if you're at 50% risk for HD, the risks of miscarriage with CVS or amnio are pretty minimal relatively speaking.

And testing asymptomatic minors is so frowned upon that it usually is not done even if newborn adoption is being considered. Which has led to some interesting issues re how to define a "sx'tic" minor.
posted by beaning at 5:27 PM on April 24, 2012

Coming in to nth the genetic testing thing. I work with a genetic counselor who specializes in HD, and our center strongly recommends against testing fetuses/children without their knowledge.

I didn't see it mentioned elsewhere, but difficulty with swallowing is a relatively common symptom in most HD patients. Also, some people find relief from some kinds of symptoms from alcohol consumption (!).
posted by kuanes at 4:11 AM on April 25, 2012

Progression of HD:

Lifting up the remote is done smoothly, but it almost looks lazy. Instead of pointing directly towards the TV, the hand takes an ehhhh its over theeerrreish type circular route. Kinda spirals in towards the goal.

Hands and feet are never still. They are always stretching, unstretching, tapping, shifting. This motion actually starts in the face - expressions are always changing, passing quickly. Eyebrows way up, then back down. Pursed lips, then stretched out, then back to neutral. Over and over and over. Expressions always look big, too. Kind of exaggerated, especially the blinking.

Slowly you notice that they are just never still. It isn't jerky. It's a kind of sliding, leaning, shifting, swaying thing that starts to affect every single movement (even sitting or laying down). At first it is subtle enough that it seems like they are just tired and a bit clumsy. They start bumping into things a little. Bumping into you.

As it progresses, stairs get tricky. They may fall. Miss where they are pouring a drink. Have trouble swallowing. Lose interest in driving. The movements increase in frequency and severity. They are always smoothed out, but lose the slight-deviation-from-intended-path look. They are obviously involuntary. Standard every day decisions with maintaining a house, finances, etc are avoided or delegated. Speech becomes less intelligible. Depression is always lurking. Then symptoms similar to dementia set in.

I'm not sure what the end looks like, yet. Feel free to contact me if you have any questions.
posted by skrozidile at 8:54 AM on May 7, 2012