Results of the extended genotyping program for patients with suspected cystic fibrosis

Abstract

Mutations in the CFTR gene were searched for in 632 patients with suspected CF from all over the Russian Federation. Testing was carried out in three stages: search for common mutations, sequencing, and search for large deletions/duplications in the CFTR gene. The molecular genetic cause of the disease was identified in 372 (58.8%) probands. In 243 of them was at the first stage of testing. The high efficiency of the common mutation screening system is further supported by the fact that in 357 (96%) patients, at least one variant was detected using the common mutation screening system. However, sequencing and searching for large rearrangements revealed pathogenic variants that occur with a higher frequency than the variants in the common mutation screening system, which indicates the need to expand this system. Clarifying and expanding the spectrum of genetic variants leading to cystic fibrosis allows it possible to improve the diagnostic system used for first-level genetic testing in cases of suspected cystic fibrosis, thereby reducing the time and financial costs of establishing a molecular genetic diagnosis and obtaining personalized therapy.