CFTR mutations in Chilean cystic fibrosis patients.

An analysis of five of the most common cystic fibrosis (CF) mutations worldwide (delta F-508, R-553X, G-551D, N-1303K and G-542X) was performed in 36 Chilean patients. Polymerase chain reaction (PCR) amplification of the DNA followed by allele specific restriction enzyme analysis was used for detection. The overall frequencies of the mutations in the chromosomes analyzed were 29.2% for delta F-508 and 4.2% for R-553X (n = 72). The G-542X, G-551D and N-1303 K mutations were absent in the Chilean sample. Our data suggest however that delta F-508 is not the most common CF mutation in Chilean patients. delta F-508 and R-553X account for only 33.4% of the alleles; 66.6% of them do not respond to the probes used and still remain uncharacterized.

[Molecular genetic study of cystic fibrosis in the Chilean population. Relationship to its clinical expression]. / Estudio genético molecular de la fibrosis quística en la población Chilena. Relación con su expresión clínica.

Aiming to establish a genotype-phenotype relationship and to search a clinical expression in heterozygotes, 25 Chilean subjects with Cystic Fibrosis and 165 relatives were subjected to a clinical-molecular study. The most common mutations found worldwide were studied: delta F-508, G-542X, N-1303K, R-553X and G551D. Clinical and laboratory assessment comprised chest X-rays, spirometry, clinical evaluation, nutritional assessment, sweat test and carotenemia. Age at diagnosis was lower among homozygotes for the mutation delta F-508. In this group, Brasfield and Schawchman scores were better, probably due to an earlier initiation of treatment. No other differences were found among genotypic groups or relatives. Genetic markers indicated a higher european component of the sample, compared to the general Chilean population.