Evaluation of clinical and genetic characteristics of cystic fibrosis patients in the Southeastern Anatolia of Turkey.

Background: Due to the amazing developments in modulatory treatments, genetic analysis of cystic fibrosis (CF) patients has become even more important. More than 2000 disease-causing variants of the cystic fibrosis transmembrane conductance regulator (CFTR) gene have been found, and their ethnic and geographical distributions vary. We aimed to present the first genetic data from the Southeastern Anatolia region of Turkey and evaluate patients' clinical and genetic characteristics and identify modulatory drugs covering a wider range of mutations by detecting and reporting new mutations.

Methods: Our study included 337 CF patients from three CF reference centers in the Southeastern Anatolia region.

Results: Ninety-one distinct mutations and four significant deletions were identified by analyzing CFTR mutations. The most prevalent mutation in our research was F508del (8.92%); the second most prevalent mutation was 2183AA->G, and the third most prevalent mutation was R347P. Additionally, a novel mutation (V1160X) was identified in two siblings. Only 33.5% of our patients qualified for CFTR modulator medication therapy.

Conclusion: This study elucidates the diverse nature of CFTR mutations in the Turkish population. The heterogenous genetic pool of the Southeastern Anatolia region is more similar to Mesopotamia than to other regions of our country, and receives immigration from the East. Detection and reporting of novel mutations and CFTR mutations that occur at very low frequencies from different populations living in various geographical areas are essential for identifying modulatory medicines that cover a broader range of mutations and also help genetic diagnosis of CF in newborn screening.