Analysis of 30 known cystic fibrosis mutations : 10 mutations account for 27 % of non-ΔF508 chromosomes in Southern France

We have analyzed 131 unrelated families from Southern France for 29 known cystic fibrosis (CF) mutations identified in 8 exons of the cystic fibrosis transmembrane regulator gene. All these mutations were detected by amplification of DNA by the polymerase chain reaction (PCR) followed by restriction enzyme digestion or hybridization with allele specific oligoprobes. The most frequent mutations after the delta F508 deletion (frequency: 63%) were G542X (5.3%), delta I507 (1.1%), and N1303K (0.76%). Seven other mutations (621 + 1G --> T, Y122X, R347P, R334W, S549N, G551D, R1162X) were each identified in only one CF chromosome. Apart from G542X, most of the other mutations identified in this study were found to be associated with 7-(GATT)-repeats allele of IVS6A. In Southern France, only 73% of CF chromosomes could be identified by the analysis of 30 mutations.