Búsqueda de la mutación delta F508 y análisis de dos polimorfismos de nucleótido único en el gen CFTR, en una muestra de población general de Valparaíso, Chile / Screening of the delta-F508 mutation and analysis of two single nucleotide polymorphism of the CFTR gene, in a sample of the general population of Valparaíso, Chile

ABSTRACT

Background: The Cystic Fibrosis (CF) carrier rate in Chile was estimated to be 1/40. CF is caused by mutations in the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene. Delta F508 mutation is the most common in CF patients in Chile and worldwide. Delta F508 has linkage disequilibrium with two Single Nucleotide Polymorphisms (SNP), often used to define the haplotypic frameworks of CF mutations. Aim: To know the frequency of the delta F508 mutation and to establish the SNPs, M470V and T854T, haplotypic frequency, in a Valparaiso general population sample. Subjects and Methods: Fifty subjects were studied. Genetic material was obtained from blood samples, amplified by PCR and analyzed by restriction fragment length polymorphism. Results: Two of the 100 chromosomes analyzed, carried the delta F508 mutation. Therefore, the observed frequency carrier rate (0.02) was higher than the expected (0.01). Both carrier chromosomes had the same SNPs haplotypic framework (1-2). In normal chromosomes, the haplotype 2-1 was the most common. Discussion: These results suggest that the chromosomes that bear delta F508 mutation have most likely a Mediterranean European origin, since this haplotypic framework has been reported in that region. We suggest that CF could be more common in Valparaiso than it was previously estimated.