Question

Duchene muscular dystrophy (DMD) is a sex-linked disorder.A female that is a carrier for DMD has a female child with a healthy male partner. What is the probability that the child has DMD?a. 100%b. 0%c. 50%d. 75%

Answer 1

A sex-linked disorder meant that the gene associated is found in the X chromosome, so for a female to have the condition it needs 2 copies of the defective gene.

Given that the mother is a carrier but the father is healthy, the probability for a FEMALE child to have DMD is 0%, so b is the right answer.