Annysa has a child with cystic fibrosis (CF) and has just gotten pregnant again. What are her odds of having a second CF child?

Question

Quizplus · Accepted Answer

CF is a recessive genetic disorder, meaning an individual must inherit two copies of the mutated gene (one from each parent) to develop the condition. If Annysa is a carrier of the CF gene, she has a 50 percent chance of passing on the mutated gene to each child. Since she already has one child with CF, we know that she is a carrier. Therefore, the chance of her passing on the CF gene to a second child is 1 in 2 or 50 percent. The odds of having two children with CF would be 1 in 4 (50 percent x 50 percent).

Annysa Has a Child with Cystic Fibrosis (CF) and Has