a boy and his brother both have hemophilia A. If there is no family history of hemophilia A in previous generations, what is the probability that the boys aunt (mothers sister) is a heterozygous carries of the disease gene
There is an actual number in the answer please help me find it.
Hemophilia is a sex-linked recessive disease.
A boy and his brother both have hemophilia so their mother is a carrier of the disease.
given that there is no familiy history of hemophilia in previous generations.
so their maternal grand mother and maternal grand father are not affected, but the maternal grand mother has to be a carrier for the mother to be a carrier.
let the alleles be XH- normal Xh- hemophila
XHXh * XHY
| XH | Xh | |
| XH | XHXH ( normal female) | XHXh ( carrier female) |
| Y | XHY ( normal male) | XhY ( hemophilic male) |
probability that the daughter is a carrier= number of carrier daughters/total number of daughters= 1/2
probability that the boys aunt (mothers sister) is a heterozygous carries of the disease gene= probability of getting a carrier daughter for a carrier woman and a normal man= 1/2.
a boy and his brother both have hemophilia A. If there is no family history of...