Suppose your mother has cystic fibrosis, which is caused by a recessive allele, but your father has a normal phenotype. However, all of your father's siblings have cystic fibrosis. What are the odds of you inheriting the disease?

Question

Quizplus · Accepted Answer

Given that cystic fibrosis is a recessive disorder, for your mother to have the disease, she must have two copies of the recessive allele (rr). Your father, having a normal phenotype but all siblings with cystic fibrosis, indicates that both of his parents were carriers (Rr), making him a carrier as well (Rr) because he does not have the disease. When a carrier (Rr) and an affected individual (rr) have a child, there is a 50% chance (1 in 2) that the child will inherit the disease (receiving the recessive allele from both parents).

Suppose Your Mother Has Cystic Fibrosis, Which Is Caused by a Recessive