Analysis of 160 CF chromosomes: detection of a novel mutation in exon 20.

The cystic fibrosis (CF) gene has been cloned and a major mutation identified (delta F508). This 3-bp deletion has been found in approximately 70% of CF chromosomes. We have used the strategy of denaturing gradient gel electrophoresis followed by direct sequencing of the polymerase chain reaction products, in order to detect other mutations in exons 10, 11 and 20 of the CF transmembrane conductance regulator gene. A new mutation, F1286-S, was found in exon 20. It involves a nucleotide change of T-->C at nucleotide 3989 and changes a phenylalanine into serine at position 1286 of the protein.