Mutation analysis of the CFTR gene in Slovak cystic fibrosis patients by DHPLC and subsequent sequencing: identification of four novel mutations.

Cystic fibrosis (CF) is the most common lethal autosomal recessive disorder in Caucasians. Its incidence is approximately 1:2500 newborns. CF is caused by mutations in the transmembrane conductance regulator (CFTR) gene, which encodes an important chloride ion channel. The disease affects the respiratory, digestive and reproductive systems. To date more than 1550 mutations and polymorphisms have been identified throughout the CFTR gene, making the DNA diagnosis more difficult. Rapid accurate identification of CFTR gene mutations is important for confirming the clinical diagnosis, for cascade screening in families at risk for CF, for understanding the correlation between genotype and phenotype, and moreover it is also the only means for prenatal diagnosis. Individuals suspect of CF are in Slovakia presently screened for the presence of 30 common mutations, giving mutation detection rate only approximately 48%. To increase the detection rate we applied a gene scanning approach using DHPLC system for analysing specifically all CFTR exons. The fragments showing abnormal elution profiles were subsequently sequenced to characterize the DNA change. We have identified a total of 28 different mutations up to present not found in Slovak CF patients, and 17 different polymorphisms. Four mutations (G437D, H954P, H1375N, and 3120+33G>T) are novel, not yet found in any other CF patient all over the word.