Cystic fibrosis mutations in Croatian CF patients

The frequency of cystic fibrosis (CF) mutations varies among different ethnic groups. Our aim was to determine the frequency of common mutations of CF patients in Croatia, Southern European and Mediterranean country, in order to develop a practical CF mutation panel that can provide maximal information for our population. PATIENTS AND METHODS: A total of 47 CF patients were diagnosed and surveyed at the Children's Hospital Zagreb, Croatia. Most of the patients were screened for 16 common mutations while some of them were screened with INNO LiPa DNA probe assay for 29 CF mutations and Tn polymorphism. RESULTS: Among 47 CF patients were identified 7 different CFTR mutations: Δ F508, F117H, G542X, N1303K, 1717-1G-A, R1162X and 621+1G>T. Δ F508 mutation was present in 66%, which was consistent with Northwest-Southeast gradient within the European population. The G542X and R117H were found each in 3.2% of Croatian CF patients. The N1303K was present in 2.1% while R1162X, 1717-1G-A and 621+1g>T were found each in 1.1% of CF chromosomes. There were 19 Δ F508 homozygotes and 10 compound Δ F508 heterozygotes with severe (3 G542X, 2 N1303K, 1 R1162X, 1 621+1G>T, 1 1717-1G-A) or mild mutation (2 R117H) on other allele. Fifteen CF patients had one mutation unknown (14 N/Δ F508 and 1 N/R117H) while 3 patients have both mutations still unknown. CONCLUSIONS: A total of 79% of CF chromosomes in Croatian CF patients carry 7 different CFTR mutations:Δ F508, R117H, G542X, N1303K, 1717-1G-A, R116X and 621+1G>T. Further studies are necessary to identify other mutations in our population in order to enable more accurate genetic counseling of Croatian CF families and to provide meaningful carrier screening and testing for rare mutations in affected individuals.