bm
Forum Elite
Topics: 37
Posts: 421
|
a male inherits x maternally and y paternally. female inherits x from each parent. one of the x in the female is randomly inactivated, therefore, there can be an affected heterozygous female who manifests the disease.
question: how can an affected male transmit the affected x to a daughter who is unaffected and transmit the same x to an affected son? assuming that the x in the unaffected daughter is inactivated (inactivation is fixed acdg to kaplan and so will all the x in the descendants)
|
| mash
Forum Fanatic
Topics: 147
Posts: 1,326
|
male wont transmit an X to his son
___________________
I hear and I forget. I see and I remember. I do and I understand.
--Confucius
|
| bm
Forum Elite
Topics: 37
Posts: 421
|
oops sorry. for clarification, male transmits to daughter and daughter to her own son (3rd generation)
|
| mash
Forum Fanatic
Topics: 147
Posts: 1,326
|
i dont remember exactly but i think x inactivation does not occur in germ cells
(x inactivation occurs on 16th day post fertilization and is random)
___________________
I hear and I forget. I see and I remember. I do and I understand.
--Confucius
|
| BumbleB
Forum Junior
Topics: 2
Posts: 83
|
You often see X linked recessives (like Hemophilia A) skipping a generation: affected grandfather->normal mother-> affected son
So go figure...
|
|
| |
| | | | | |
