Cystic fibrosis is a recessive genetic disorder, meaning that a person must inherit two copies of the faulty gene, one from each parent, to develop the condition.
The faulty gene disrupts the function of a protein called cystic fibrosis transmembrane conductance regulator (CFTR). This protein is responsible for transporting chloride ions across cell membranes, which in turn affects the movement of water.
When CFTR doesn't work properly, it leads to the production of thick, sticky mucus that can clog the lungs, pancreas, liver, intestines, and other organs.
