How is cystic fibrosis inherited?

Cystic fibrosis is an inherited genetic disorder that affects the lungs and digestive system. It is caused by a mutation of the gene that produces a protein called cystic fibrosis transmembrane conductance regulator (CFTR). The mutant gene makes the protein unable to work properly, leading to a buildup of thick mucus in the lungs and other organs.

Cystic fibrosis is inherited in an autosomal recessive pattern, which means that both parents must carry the CFTR mutation for a child to be at risk for the disorder. If both parents are carriers, there is a 25% chance that their child will have the disease. If only one parent is a carrier, the child will not have cystic fibrosis, but will be a carrier like the parent.

It is important to know that cystic fibrosis is not contagious, and it cannot be passed from person to person. Also, not everyone who carries the CFTR mutation will develop cystic fibrosis. Even if both parents are carriers, there is still a 75% chance that their child will not have the disorder. Therefore, genetic testing is the only way to know if someone is a carrier of the mutation.