[Prenatal molecular diagnosis of cystic fibrosis. Report of 3 cases].

Cystic Fibrosis (CF) is a severe and relatively common autosomic recessive disease caused by a variety of mutations in the CFTR gene. The most frequent mutation worldwide, consists of the deletion of the phenylalanine codon at position 508 (delta F508). Here we report the first cases of prenatal diagnosis of CF by DNA analysis in couples at risk in Venezuela. The study focused on the detection of delta F508 alleles analyzing DNA recovered directly from amniocytes or from their cultures, using the polymerase chain reaction (PCR) and polyacrylamide gel electrophoresis. Two of three fetuses resulted homozygotic for the delta F508 allele and the third one turned out to be a delta F508 carrier. This information sustained the genetic counseling of the couples and allowed them to take objective reproductive decisions, a direct consequence of the availability of gene analysis at the DNA level.