Distribution of cystic fibrosis mutations and the three microsatelite loci in Croatian population

Cystic fibrosis is one of the most common recessive disorders in Caucasian affecting approximately 1 in 3000 individuals. More than 1000 mutations have been identified in cystic fibrosis transmembrane conductance regulator gene (CFTR). The most frequent mutation, accounted for about 67% CF chromosomes, is Δ F508. Only four others (G542X, N1303K, G551D and W1282X) have frequencies higher than 1% ; most other are rare and specific for some population subgroups. The southern-east region of Europe is highly heterogenic and CF mutation analysis can be facilitated by association studies between intragenic polymorphic haplotypes. The aim of this study was to reveal the frequency of 29 CF mutations along with the distribution of three polymorphic loci (IVS 1 CA, IVS 8 CA and IVS 17b CA) and associated hapoltypes in diseased population. A total of 41 unrelated CF patients from Croatia were included in this study which revealed 6 different mutations accounted for 68, 29% diseased alleles. The most frequent mutation was Δ F508 (58, 74%), followed by G542X (3.66%) and N1303K (2.44%). Polymorphic loci analysis revealed high level of heterogeneity, 15 different haplotypes were found. The most frequent associated with CF was 21-23-13 (23, 2%), followed by 21-17-13 being the most frequent one (31, 3%). According to our results it can be concluded that genetic background of cystic fibrosis in Croatian population is more complex than it was expected. Much more work is needed to get inside the exact population screening with available kits and association studies.