I am constantly seeing that the chance of inheriting HD from an affected parent is 50/50, but I can't find any research that's been done to confirm it. Can anyone point me in the right direction?

I also seem to recall seeing an article quite a while ago that suggested that there might be factors that skewed the 50/50 and it might be more like 53/47 - does anyone remember that article?

The statistic is based on a knowledge of genetics. HD is a dominant gene. If a parent has one copy of it (the usual situation here in the U.S.) and the other parent has two normal huntingtin protein genes, then the chances are 50-50 that a child will get the HD gene -- or the normal gene. If one parent has a gene for brown eyes (which is dominant), and one for blue (recessive) and the other parent has two genes for blue eyes, the chances of having a brown eyed child is 50-50.

I am unaware of any article suggesting it was not 50-50 in the above scenario.

There are other scenarios. If a parent has two HD genes (common in Lake Maracaibo), then the child will receive an HD gene. If both parents have a normal gene and an HD gene, then the child's chances of getting the HD gene are 75 percent.

Shrimpy, you don't always have to inherit. It is possible as I understand for HD to manifest itself in a person. I certainly can't explain that concept but this is what I was told. I do believe my expansion came from my Father who passed away at 57 and I was 6. I would guess his CAG was in the 30-35 range or so???? I won't ever really know.
Mike

Thanks Marsha, I understand that, but the suggestion I have seen is that a foetus carrying the HD gene might be slightly more likely to carry to term than one without. I would have thought that, with the wealth of data now available to HD researchers it would be fairly easy to check something like this.

How often have new insights in science been gained when people double checked what they thought they already knew?

Hi Mike,

Thanks for the input, I had heard of the possibility of an expanded CAG pushing someone into the HD category and it is really interesting to hear from someone it has happened to. No possibility of obtaining any of your Dad's DNA even now (hairbrush, locket with hair :-) )? It would be fascinating to know what his CAG was.

Tom

You know, I never thought about that. My Dad died at 57 and I was 6. I am now close to 57 so my Dad passed away some 50 years ago. I am not aware of anything that may lead to DNA but I will certainly check around.

The Neuro had to make some assumtions in my case which I completly understand. There is a possibillity it manifested itself in me. Sort of like a si-fi thriller I guess. Unfortuately, my children have to deal with this.

As I was finishing I had a moment; I have his pipes.............good idea.........

Hang in there buddy.

Mike