Screening for non-delta F508 mutations in five exons of the cystic fibrosis transmembrane conductance regulator (CFTR) gene in Italy.

Analysis of exons 10, 11, 14a, 15, and 20 of the cystic fibrosis transmembrane conductance regulator (CFTR) gene by denaturing-gradient-gel electrophoresis (DGGE) allowed the identification of mutations causing cystic fibrosis (CF) in 25 of 109 non-delta F508 chromosomes, as well as identification of a number of polymorphisms and sequence variations. Direct sequencing of the PCR fragments which showed an altered electrophoretic behavior not attributable to known mutations has led to the characterization of four new mutations, two in exon 11, and one each in exons 15 and 20. Screening for the different mutations thus far identified in our patients by the DGGE analysis and other independent methods should allow detection of about 70% of the molecular defects causing CF in Italy. Mutations located in exons 11 and 20 account for at least 30% of the non-delta F508 mutations present in Italian CF patients.