Читать книгу Genetic Analysis of Complex Disease - Группа авторов - Страница 52

Cystic fibrosis (CF), an autosomal recessive disorder, is the most common hereditary disease among Northern Europeans, with a carrier frequency of between 1/25 and 1/30 (Hamosh et al. 1998). This condition affects the function of the pancreas, lungs, and sweat glands, among other organ systems (Ratjen and Doring 2003). In Northern Europeans, a single mutation in the CFTR gene called ΔF508 accounts for about 70% of the abnormal CF alleles. Three bp (codon 508) are deleted, and the resulting amino acid sequence is missing a phenylalanine. Although the reading frame is preserved in this particular mutation, the deletion results in a block in protein processing. CF is an excellent example of allelic heterogeneity in which different mutations, or alleles, at the same locus can cause a disease. In fact, more than 1900 other deleterious mutations in CFTR have been identified (Cystic Fibrosis Mutation Database 2015).