Cystic Fibrosis Inheritance: Understanding Autosomal Recessiveness

Cystic fibrosis is an autosomal recessive genetic disorder. This means that both copies of the gene that codes for the protein CFTR (cystic fibrosis transmembrane conductance regulator) must have mutations in order for the disease to develop.

A person who has only one mutated copy of the CFTR gene is called a carrier. Carriers do not have cystic fibrosis themselves, but they can pass the mutated gene on to their children.

If both parents are carriers, there is a 1 in 4 chance that each of their children will have cystic fibrosis. There is also a 1 in 2 chance that each of their children will be a carrier.

Cystic fibrosis is the most common life-threatening genetic disorder in the United States. It affects about 30,000 people in the United States and about 70,000 people worldwide.