Mohsen Reisi - Pediatric Department, Child Growth and Developmental Research Center, Research Institute for Primordial Prevention of Non-Communicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran.
Mahdiyeh Behnam - Medical Genetics Laboratory of Genome, Isfahan, Iran.
Seyed Javad Sayedi - Neonatal Research Center, Akbar Hospital, Mashhad University of Medical Sciences, Mashhad, Iran.
Farzaneh Salimi - Medical Genetics Laboratory of Genome, Isfahan, Iran.

Background: Cystic fibrosis (CF) is the most common lethal genetic disorder of Cystic Fibrosis Trans-membrane Conductance (CFTR) Regulator gene mutations. We aimed to investigate common mutations in CF patients and to assess its possible relationship with clinical presentations. Materials and Methods: This cross sectional study was conducted on 36 CF patients who were referred to a tertiary pediatric hospital in Isfahan, Iran. They were evaluated for 34 common mutations in CFTR gene by using reverse dot blot strip assay. Other parameters such as the age of diagnosis, the sweat chloride level, and clinical manifestations due to lung involvement and pancreatic insufficiency were also assessed. According to genotype mutations, children were divided in three groups: ΔF508 mutation (group 1), non-ΔF508 mutation (group 2), without current mutations (group 3). Finally, genotype, and phenotype relationship were reported. Results: The mean age of patients was 8.1+2.3 months, and 23 of them (63%) were male. CFTR mutations were found in fourteen patients (38.8%). ΔF508 mutation has the highest prevalence in the studied samples with allele frequency of 15.27%, and c. 2183 AA> G was in the second standing.  Furthermore, p.R553X, p.G542X, C.1766+1, p.N1303K mutated alleles also were obtained in lower level. Mean age at the diagnosis time of CF, sweat chloride level and pancreatic insufficiency were not different between groups but lung complications were significant in children with common mutations. Conclusion: Our findings showed that commercial kit designed to identify 34 common CFTR mutations failed to detect 61.2% of alleles of our patients. This necessitates designing local diagnostic kits for proper diagnosis of CF in Iranian children.

Children, Cystic fibrosis, mutations, Prevalence, sweat test