How is cystic fibrosis inherited?

Cystic fibrosis is inherited in an autosomal recessive manner, meaning both parents must carry the faulty gene.

Cystic fibrosis (CF) is a genetic disorder, which means it is passed down from parents to their children through their genes. It is specifically an autosomal recessive disorder. This means that a person must inherit two copies of the faulty gene, one from each parent, to have the condition. If they only inherit one copy, they will not develop the disease but will be a carrier.

The gene responsible for CF is called the CFTR gene. This gene makes a protein that controls the movement of salt and water in and out of your body's cells. In people with CF, this gene is faulty, which leads to the build-up of thick, sticky mucus in the body's tubes and passageways.

Each person has two copies of the CFTR gene. When both parents are carriers, there is a 25% chance their child will have CF, a 50% chance the child will be a carrier, and a 25% chance the child will neither have CF nor be a carrier. This is because each parent passes on one of their two CFTR genes to their child. If a child inherits one faulty CFTR gene, they will be a carrier. If they inherit two faulty genes, they will have CF.

It's important to note that being a carrier of CF, meaning you have one faulty CFTR gene, does not affect your health in any way. However, you could pass the faulty gene onto your children. Genetic counselling can provide more information for those who are carriers or have a family history of CF.