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 ide ntified (DELTAF508). This 3-bp deletion has been found in approximatel y 70% of CF chromosomes. We have used the strategy of denaturing gradi ent gel electrophoresis followed by direct sequencing of the polymeras e chain reaction products, in order to detect other mutations in exons 10, 11 and 20 of the CF transmembrane conductance regulator gene. A n ew mutation, F1286-S, was found in exon 20. It involves a nucleotide c hange of T-->C at nucleotide 3989 and changes a phenylalanine into ser ine at position 1286 of the protein.