Question

Fragile X syndrome is a genetic condition caused by mutations in the FMR1 gene. Knowing that the trait is inherited as an X-linked recessive condition, you would be able to tell the woman that she has __ chance of carrying one mutant copy of the FMR1 gene.

a) 25%
b) 50%
c) 75%
d) 0%

Answer 1

A woman has a 50% chance of carrying one mutant copy of the FMR1 gene.

Step-by-step explanation:

Fragile X syndrome is an X-linked recessive condition, which means that it is carried on the X chromosome. Women have two X chromosomes, one from each parent. If a woman carries one mutant copy of the FMR1 gene on one of her X chromosomes, she is considered a carrier. Since the trait is X-linked recessive, she has a 50% chance of carrying one mutant copy of the FMR1 gene.