Cystic Fibrosis Transmembrane Conductance Regulator Mutation Spectrum in Patients with Cystic Fibrosis in Tunisia

Aim: To determine the frequency and types of mutations causing cystic fibrosis (CF) in Tunisia. Methods: We analyzed the complete coding region and flanking intronic sequences of the cystic fibrosis transmembrane conductance regulator (CFTR) gene in 68 unrelated patients suffering from the classical form of the disease. Results: Twelve different CFTR mutations accounted for 90% (123/136) of CF alleles, including F508del (47.06%), E1104X (16.18%), N1303K (6.62%), 711 + 1T> G (5.88%), W1282X (4.41%), G542X (3.67%), R1158X (1.47%), 4016insT (0.74%), and R785X (0.74%). Three novel mutations were detected in this study: I1203V (1.47%), 1811 + 5A > G (0.74%), and 4268 + 2T > G (1.47%). Fifty patients (74%) were homozygous, among which 28 (41.17%) for F508del and 10 (14.7%) for E1104X. Conclusions: Ninety-seven percent of patients were found with at least one CFTR mutation. This study contributes to a better knowledge on CF-causing mutations in different regions in Tunisia and demonstrates that a complete scanning of CFTR sequences is necessary to implement efficient programs for CF genetic screening and counseling in this part of North Africa.