Prevalence and Nationality Distribution of Known and Novel Genetic Variants in Children With Primary Ciliary Dyskinesia in the State of Qatar

Abstract

Primary ciliary dyskinesia (PCD) is a genetic disease caused by variants affecting more than 50 cilia genes. We report the prevalence and distribution of all known and novel variants in children with PCD in Qatar. The cohort included 28 children: 16 Qatari, 3 Egyptian, 2 Tunisian, 1 Sudanese, 1 Algerian, 1 Pakistani, 2 Iranian, and 2 Indian. Consanguinity rate was 82.1%. Median age at diagnosis was 7.5 years (IQR: 0.6–11.8). Situs inversus was present in 7 (25%) patients, chronic cough in 25 (89.3%), chronic sinusitis in 17 (60.7%), and bronchiectasis in 16 (61%). Median FEV1 was 71% (IQR: 58%–82%), FVC was 80% (IQR: 74%–91%), and FEV1/FVC ratio was 79% (IQR: 68%–84%). The most frequent variant in native Qataris was c.5924+1G>C in DNAH11 (seven patients). Eight novel variants were found in the cohort: c.6565C>T in DNAH11 (two patients); c.368-369del in DNAAF3 (one patient); c.357G>A in DNAFF2 (one patient); c.278G>A in DNAAF2 (one patient); c.1666-9C>G (intronic) in CCDC39 (two patients); c.9105+2T>C (splice donor) in DNAH5 (two patients); c.8647+3A>G (intronic) in DNAH5 (two patients); c.916G>T in ODAD4 gene (two patients). Wide genetic variation was found among PCD children in Qatar, including several novel variants, reflecting their ethnic diversity. Genetic variation was less among native Qatari patients due to high consanguinity.