The pregnant mother of a 6-yr-old son with G6PD deficiency is very worried that her female fetus will have the disease. The father and mother are clinically normal. Which of the following is true about her baby?
A. The baby has a 25% chance of clinical disease
B. The baby has a 50% chance of being a carrier
C. The baby has a 50% chance of clinical disease
D. The baby will be a carrier
E. The baby will have clinical disease
A. The baby has a 25% chance of clinical disease
There is something missing from this question but for anything B would be the correct answer this a X-linked recessive disease, then it is a male disease, all male will be affected and the female will probably be a carrier if X methylation of the X chromosome
sorry guys ,u are right
i thought that the baby is male
its XR and mother is clinically normal that means she is carrier of affected allele (hetro)so thats why not all but only 50% males wud have been affected.and 50% females carrier.
correct ans is B. it's an X-linked recessive and mother is a carrier.
to docm: glad you brought up the X methylation thing. are you talking about the "manifesting heterozygote"? if the normal X is inactivated, the female carrier manifests the disease, right? I think if they want us to take into consideration the X inactivation thing, they would have clued us in on it. I mean, there's no way of solving the probability if we also include the X inactivation, right? or is there? please share us what you know. thanks!
okazakimd, ur understanding to this q is right
the ans is D . the females are carrier but all male show the diseaze. it s x linked recessive.
look it up