The Facts
Cystic fibrosis (CF) is an inherited (genetic) disease in which excess mucus clogs the lungs, prevents food from being digested, and damages the reproductive system. It is the most common life-threatening genetically inherited disease affecting Caucasians. About 30,000 children and adults in the United States, mostly Caucasians, have cystic fibrosis.
In CF, an abnormal protein called CFTR is produced. This protein changes the way chloride (a component of salt, which is also called sodium chloride) moves in and out of cells. This affects the balance between salt and water in the body, making the mucus that lines the lungs, pancreas, and other organs thicker and stickier.
CF affects all the body's exocrine glands. These glands create chemicals necessary for proper functioning of the body. The pancreas, for example, is an exocrine gland that provides digestive enzymes for the stomach. The sweat glands provide liquid to cool the skin. In CF, some glands produce abnormal substances. The sweat glands, for example, release high levels of salt. Other glands, like the pancreas, become plugged with mucus. Because it affects so many organs in our body, CF is usually diagnosed early in childhood.
The tables below show your risk of being a CF carrier based on which family members have CF or on your ethnicity:
| Relative with CF |
Your carrier risk |
| Parent or child |
1 in 1 (100%) |
| Siblings |
2 in 3 (67%) |
| Niece or nephew |
1 in 2 (50%) |
| Aunt or uncle |
1 in 3 (33%) |
| Cousin |
1 in 4 (25%) |
| Ethnicity |
Carrier risk |
| Caucasian (white, European ancestry) |
1 in 25 |
| Ashkenazi Jewish |
1 in 25 |
| Hispanic |
1 in 46 |
| African American |
1 in 65 |
| Asian |
1 in 90 |
Thanks to good research, better and more medications, and early diagnosis, people with CF are living longer, fuller lives.