My Family learned about Huntington's Chorea, back in 1954 when my parents checked on the death of my Grandfather. My Grandfather was institutionalized in 1928 as an "inebriate" and while at the hospital it was discoved that he had Huntington's Chorea. Several of his children did inherited the disease and have unknowingly passed it on to their children. From what I have been able to discover, (doing genealog), there are about 25 - 30 family members which have inherited HD. For the past 60+ years I have always heard that Huntington's DOES NOT skip generations. If your parent does not have it then it has stopped in that paticular line and will NOT pass to the next generation. Therefore I was not concerned after my father and later myself, reached and passed the average age of onset for my family, about 30-35 yrs. That once it stops in a paticular line, it does not continue on. My father died at the age of 68 without ever showing any signs of inheriting HD. However several of his brother and sisters did inherit the disease and it has continued on in their line. Recently I was told that research has proven that it can and does skip generations !!
Is this new information correct, and should I again be concerned for my children and grandchildre?
My FIL wasn't diagnosed with HD until he was in his 70's. That in not typical, but can happen. We never knew it was in the family. It really doesn't skip generations, but there is a gray area of the mid-to-upper 30's where a person may or may not develop the symptoms of HD. Sometimes the CAG counts can mutate down (but they usually mutate upwards) and then mutate up again for a child of future generations. That's one way it could be appearing to "skip". An individual won't know unless he or she is tested.
I have never heard that. I know in rare circumstances that you can be the first in a family line to get it, ie. a new mutation stemming from intermediate CAG counts (29-36..).
According to my test results, the genetic company states that I won't pass on the gene because I did not inherit it. Nothing about skipping generations.
I would evaluate your source of information; unfortunately many medical professionals are not really knowledgeable about this disease. I have been told that only males can get HD (by a doctor) and that is completely false!
I would suggest testing just so you know your CAG counts; it may give you the assurance that you are looking for (for your children).
When the gene passes from a parent to a child, the gene can expand or contract. This happens more often for fathers passing the gene to their children. Technically a parent can pass a contracted gene to their child and the child ends up with a lower cag number (perhaps even in the grey region where an individual may not live long enough to have symptoms of the gene). Then that child could pass on an expanded gene to their child (cag above 40). Technically the huntingtons gene is still being passed, but the cag number is different. Symptoms of huntingtons could skip a generation. I'm sure someone on this forum would know more.
Thank you all for your help. I really thought that I was past "living at risk" for HD. . I was 16 or so when my Uncles Dr. told my cousin and I that the only way to stop the disease, was for all the females not to have children. I went on with my life, of course, thinking that "it won't happen to me" There wasn't any genetic testing then. then after so many years of no symptons in my Dad or in myself, I felt that we were the fortunate ones, and safe from this disease. Dad died in 1988 at 68 years old with inoperable cancer. I am now in my late 60's with no signs or symptons of HD, so I'm pretty sure that I am clear, but now with this new info to me, of HD skipping generations, I'm not so sure. I really don't understand what a CAG but perhaps I should check with the Dr. to get tested just for peace of mind. Thanks you again
I am the first in my family. My CAG is 36. Came about from a head injury. I've not heard of geration skipping. I guess it would be good?The Neuro did think mine came from my father who died at 57 when I was 6. We will never know. Apparently I lived to see HD with a 36.. I have had other similar post.
It's good to know it may skip as I have two sons at risk. I've learned a lot about HD here. This is a wonderful community. Thanks to you all..I believe Marsha may be able to shed some light on this.
Who was it that told you hd can skip a generation? We used to think that in my family too, but no, it absolutely does NOT skip generations. Mae88 explained it the best. Sometimes "Symptoms" can skip a generation, if that person dies before they get symptoms, or if there is a cag contraction. My dads sister had hd, along with many cousines, etc, buth my dads's father and grandfather died around age 70, supposedly symptom free, from heart attacks. I became symptomatic at age 45, and was diagnosed with hd a year later. My father became symptomatic 5 years After me, in his mid 70's. My neuro says, if his father and grandfather had lived longer, they would have gotten hd absolutely for sure. Hope this helps. And in some people like Mikee, there can be brand new cases of hd, with no previous history. But in my family, there was a very clear history of it, starting with my great-great-great grandfather, who had many siblings with hd, then it seemed to skip a couple generations, which it didn't really.
Edited 2 time(s). Last edit at 05/03/2012 12:02PM by Barb.
If you have the hd gene which expresses an elevated cag repeat whether or not you become symptomatic or not you still have the gene. It can possibly be passed to the next generation at that same elevated but low mutated count and that person also may never be symtomatic. Then passed again in the next generation and possibly mutate into a higher count which might make that person show symptoms earlier. All three had the mutated gene, but because of a somewhat lower CAG count it just didn't cause an expression of symptoms in all. If all had lived to be very old it would have shown at some time.