[Molecular-genetic analysis of certain mutations of the "cystic fibrosis gene" in Moldavia. Characteristics of molecular markers and their linkage with various mutations].

Sixty-one patients with cystic fibrosis (CF) from Moldova were tested for mutations delta F508, G551D, and R553X. Frequencies of various alleles of the repeated GATT sequence in intron 6B of the CFTR gene, their linkage to other polymorphic markers, and various mutations were determined. The frequency of occurrence of mutation delta F508 was only 25%. An absolute majority of CF patients (80%) had pancreatic insufficiency. Mutations G551D and R553X were not found in our sample. Each of 31 chromosomes with mutation delta F508 carries the 6-GATT allele. Most "non delta F508" (78%) and normal (80%) chromosomes were marked by 7-GATT allele. Twenty-seven delta F508 chromosomes (96.4%) belong to haplotype B6, and only one to D6. Most chromosomes with "non delta F508" mutations are associated with haplotypes D7 (26.3%) and C7 (21%). In addition, a significant portion of chromosomes from this subgroup were associated with haplotypes A7 (23.7%), A6 (10.5%), and C6 (2.7%), which are not yet described for mutant chromosomes. The results obtained demonstrate that CF in Moldova is mainly associated with mutations other than delta F508, G551D, and R553X. Severe forms of the disease, with pancreatic insufficiency, are more frequently caused by these mutations; moreover, our data provides strong evidence about the presence of at least seven additional CF mutations in Moldova, apart from delta F508, G551D, and R553X. Some of these are probably not described.