Cystic Fibrosis - Epidemiology

Epidemiology

Cystic fibrosis is the most common life-limiting autosomal recessive disease among people of Caucasian heritage. In the United States, approximately 30,000 individuals have CF; most are diagnosed by six months of age. In Canada, there are approximately 3,500 people with CF. Approximately 1 in 25 people of European descent, and one in 30 of Caucasian Americans, is a carrier of a cystic fibrosis mutation. Although CF is less common in these groups, approximately 1 in 46 Hispanics, 1 in 65 Africans and 1 in 90 Asians carry at least one abnormal CFTR gene. Ireland has the world's highest incidence of cystic fibrosis, at 1:1353.

Although technically a rare disease, cystic fibrosis is ranked as one of the most widespread life-shortening genetic diseases. It is most common among nations in the Western world. An exception is Finland, where only one in 80 people carry a CF mutation. In the United States, 1 in 4,000 children are born with CF. In 1997, about 1 in 3,300 caucasian children in the United States was born with cystic fibrosis. In contrast, only 1 in 15,000 African American children suffered from cystic fibrosis, and in Asian Americans the rate was even lower at 1 in 32,000.

Cystic fibrosis is diagnosed in males and females equally. For reasons that remain unclear, data has shown that males tend to have a longer life expectancy than females, however recent studies suggest this gender gap may no longer exist perhaps due to improvements in health care facilities, while a recent study from Ireland identified a link between the female hormone oestrogen and worse outcomes in CF.

The distribution of CF alleles varies among populations. The frequency of ΔF508 carriers has been estimated at 1:200 in northern Sweden, 1:143 in Lithuanians, and 1:38 in Denmark. No ΔF508 carriers were found among 171 Finns and 151 Saami people. ΔF508 does occur in Finland, but it is a minority allele there. Cystic fibrosis is known to occur in only 20 families (pedigrees) in Finland.