CF Genetics

Cystic fibrosis is a genetic condition that affects around 1 in every 2,500 babies. It is caused by mutations in the gene that produces the CFTR protein. This protein regulates the movement of salt and fluids in and out of cells in many parts of the body. Mutations in the CFTR gene cause the protein to either not be made in the first place or to malfunction which leads to a buildup of mucus. This leads to complications in many organs within the body - such as persistent infections in the lungs and destruction of the pancreas.

As many as 1 in 25 people are carriers of a cystic fibrosis mutation.

CF is a recessive genetic condition. This means that in order to have cystic fibrosis, a child must inherit two copies of a mutated CFTR gene. If someone only has one mutated copy of the CFTR gene and the other copy is normal, then he or she does not have CF and instead they are a CF carrier.

Each time two CF carriers have a child together, the chances are:
- 25 percent (1 in 4) the child will have CF
- 50 percent (1 in 2) the child will be a carrier but will not have CF
2- 5 percent (1 in 4) the child will not be a carrier of the gene and will not have CF

People with CF can also pass copies of their CFTR gene mutations to their children. If someone with CF has a child with a CF carrier, the chances are:
- 50 percent (1 in 2) the child will have CF
- 50 percent (1 in 2) the child will be a carrier but will not have CF