Cystic fibrosis (CF) is a genetic disease affecting approximately 30,000 children and adults in the United States. A defective gene causes the body to produce an abnormally thick, sticky mucus that clogs the lungs and leads to life-threatening lung infections. These thick secretions also obstruct the pancreas, preventing digestive enzymes from reaching the intestines to help break down and absorb food. The mucus also can block the bile duct in the liver, eventually causing permanent liver damage in approximately six percent of people with CF.
More than 10 million Americans are unknowing, symptomless carriers of the defective CF gene. An individual must inherit two defective CF genes—one from each parent—to have CF. Each time two carriers conceive, there is a 25 percent chance that their child will have CF; a 50 percent chance that the child will be a carrier of the CF gene; and a 25 percent chance that the child will be a non-carrier.
CF occurs in approximately one of every 3,500 live births. About 1,000 new cases of CF are diagnosed each year. More than 80 percent of patients are diagnosed by age three; however, nearly 10 percent of newly diagnosed cases are age 18 or older.