A comprehensive CFTR mutation analysis of German cystic fibrosis patients

Cystic fibrosis (CF) is one of the most frequent genetic diseases among Caucasian populations and caused by mutations in both alleles of the 'cystic fibrosis transmembrane conductance regulator ' (CFTR) gene (1, 2, 3). A complete analysis of all functional regions of the CFTR gene has hitherto been performed for French patients (4) and a Celtic subpopulation (5). Molecular genetic analysis of 250 German CF patients yielded allele frequencies as shown in Table 1. The remaining 68 alleles bearing unknown mutations were screened for mutations in exon 13, 20 and 21. Exon 13 was amplified in two overlapping segments of approximately 400 bp and scanned for mutations by a non-radioactive version of chemical cleavage of mismatch (6). Only an amino-acid neutral variation (L749L; CTG—TTG) was found heterozygous in a single patient. In exon 20, the mutation W1282X (7) was found three times and the mutatio