Can a child inherite JHD from their mother?
Katrina Hamel: So, the next question is for Dr. Wheelock. Can JHD be given to child by their mother. We hear this debate inside of the different online Facebook groups. I'm glad someone asked it because we've been hearing a lot of, false information, as far as I know, as far as if moms can give their children JHD.
Dr. Vicki Wheelock: Yeah, thank you. So Juvenile Onset Huntington's can come from either mother or father, but statistically it's a bit more common to come from a father.
And the reason for that is because the CAG expansion, the number of CAG repeats can be expanded from one generation to the next. Spermatozoa may have extra copies of the CAG, attached to them and up to, up to 20 more copies, actually quite a few. That's not very common by the way. Whereas in the ova and the egg, it's usually around plus or minus two from what the mom's CAG repeat length is. So there's a biological reason that it's more commonly inherited from a father, but absolutely it can be inherited from a mother, without a doubt. So, I think it's a pretty straightforward answer.
Katrina Hamel: Thank you.