Huntington Disease Lighthouse Families

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Reduced penetrance - age of onset

Posted by lisaditisme 
Reduced penetrance - age of onset
August 27, 2016 11:23AM
I wanted to know if someone with 36-39 repeats could ever develop symptoms in their 30s? I recently tested positive with 39 repeats. I am 34 years old and have felt a little "off" for the past year or so (before we even knew HD was in my family). It started with memory issues, my friends would laugh because I would repeat myself a lot. More recently I have been having moments where I am speaking and I get stuck because I can't think of the word I am looking for. My boyfriend had also noticed that I was constantly moving the toes on one foot. My Dr said that with 39 repeats I am too young to be symptomatic. I am trying to conceive, and really want to know what is going on with me before I get pregnant. Is it possible that someone could be symptomatic at my age? My family and friends tell me that its probably just stress or related to my depression but I don't think that's the case. I don't feel like myself and its uncharacteristic for me to have these issues. It's to the point that I am pulling away from people because it's embarrassing to forget you have already told someone something or to get stuck trying to find a simple word. I have an appointment with the movement disorder Dr in October, and I am curious if there is a way for the neurologist to say with certainty that someone is symptomatic or not? Could imaging of the brain show for sure if someone is developing symptoms?
Re: Reduced penetrance - age of onset
August 31, 2016 06:39PM

It does seem like you are very young to experience symptoms when the CAG count is only 39. Stress and worry can have a profound effect on our minds and bodies. I hope that is all it is.
However, to answer your question about the neurologist, they do an in office exam consisting of a number of questions and small tasks that they have you do which is apparently a very good indicator of whether or not someone is actually symptomatic. I remember my husband going through it several times. I have read that brain imaging is NOT reliable as many people with HD who do have symptoms don't have noticeable abnormalities that show up on scans until very late in the progression of the disease.
Good luck!
Re: Reduced penetrance - age of onset
September 16, 2016 03:21PM
Hey Lisa, I haven't been on here in awhile, but just saw your post and wanted to reply to you. I have a cag of 39, am 59 years old now, and still very very early stage. I became symptomatic around age 42, and did the bloodwork and neuro exam at age 44, I came out positive and I was also symptomatic. It's not just memory and thinking tests that they do. They do certain physical tests, having you walk a straight line, they watch your gait, all kinds of things like that. I had small memory problems, slight problem with my gait, and a problem with my eyes. They take their finger and and ask you to follow their finger as they move it, they can tell watching your eyes follow their finger if you have slow eye saccades, which I guess is like slow response to following their finger, and I had slow eye saccades, so there are certain physical tests that really do tell them if a person is showing symptoms. I was also told that a cag of 39 is very unpredictable, they said it's like a wild card, and kind of does what it wants to do, compared with higher cag's where they can predict age of onset, they said a 39 is more wild. The reason they said this to me, was because I was now symptomatic before my dad, my dad didn't become symptomatic until about 4 years after me, in his mid 70's. The good news, I think because i'm a 39 might be one of the reasons my hd is not getting worse quickly, but rather doing really good. Best wishes to you
Re: Reduced penetrance - age of onset
October 24, 2016 09:08AM
Hello Lisa. It's been a long time since I posted but your post was of particular interest. Like Barb, I am 59 and in the reduced penetrance range with a CAG of 36. I became symptomatic around 52. This range seems so unpredictable even to the point I have heard neurologist say it's almost impossible to be symptomatic. Needless to say, I don't see them.

Barb is correct about all of the test they use. I had to go to Mayo (after 2 misdiagnosed issues) and they are great.

Until 1992 HD was diagnosed based on those physical and physchological findings alone. Then came genetic testing. Personally I had no idea what HD was when tested.

If you aren't comfortable with what you are finding out, I suggest you look into another specialist. I have found that even many Neurologist are not familiar with all he details of HD unless they treat or have specialty status (understandably). For what it's worth, be your own advocate and don't give up until convinced you have found an answer.

Somewhere on the sight is an article I wrote some years back that may help you with some of the uncertainty, it was about a lot of uncertainty for sure..

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