Answer:
50% or 1/2. The result remains unchanged if the husband were to have G6PD.
Explanation:
For X-linked recessive inheritance, a female (XX) needs two recessive alleles to be affected while a male needs only one (XY). It is hypothetically assumed that the Y chromosome does not carry any trait.
Assuming the allele for the disease is represented by g, a woman whose father suffered from G6PD is a carrier for the disease with genotype . A normal man will have the genotype
. When the 2 marries:
x
=
It thus means that 50% or 1/2 of their sons will be expected to have G6PD.
Now, assuming the husband has G6PD, the mating becomes:
x
=
50% or 1/2 of their sons is still expected to have G6PD. The ratio remains unchanged.