There are more than 1200 mutations of the CFTR gene that cause cystic fibrosis, but the most common mutation is Delta F508. People with Delta F508 usually have more severe symptoms and are almost always diagnosed in early childhood. About 7% of the time, people with mutations other than Delta F508 may have a milder form of cystic fibrosis that does not produce troubling symptoms until later in life.
The tests used to diagnose cystic fibrosis in adulthood are the same as tests used to diagnose childhood CF. When symptoms first start to appear, doctors may not think of cystic fibrosis because it is so uncommon. At some point after ruling out other diseases, the doctor may suspect CF and order a sweat test.
Because they have milder forms of the disease, people who are diagnosed with CF later in life generally have less complications, less hospitalizations, and less need to take enzymes than people who are diagnosed in childhood.
Source:
Widerman,E., PhD, Millner, L., PhD, Sexauer, W., MD, FCCP and Fiel, S., MD, FCCP. “Health Status and Sociodemographic Characteristics of Adults Receiving a Cystic Fibrosis Diagnosis After Age 18 Years”. Chest. 2000 118:427-433.
