00:01
So the question says, what type of inheritance pattern is the following pedigree consistent with? so we're going to go through each of the options and we're going to explain why they do fit or don't.
00:08
X -linked recessive.
00:11
So we notice that in generation two, person eight and nine, neither of them have the disease, but one of their daughters does.
00:22
If this was x -linked recessive, in order for a daughter to get the disease, the dad would also have to have it, but he doesn't.
00:30
So it is not x -linked recessive because that generation 2 parent 8 and 9 and daughter 17, that is showing that that's not the case.
00:41
Autosomal dominant, so it's not related to sex chromosomes.
00:52
So in an autosomal dominant fashion, if this was, we couldn't have, again, person 8 and 9, neither of them have it, but their daughter 17 does.
01:04
Does.
01:05
If it's autosomal dominant, it is impossible for you to have a child that has the disease when neither parent does, unless it's a random mutation that occurs, but the pedigree doesn't say that.
01:15
This runs in that family...