DNAH11 variants and its association with congenital heart disease and heterotaxy syndrome.

Congenital heart diseases (CHDs) are the most common types of birth defects, affecting approximately 1% of live births and remaining the leading cause of mortality. CHD patients often show a higher incidence of heterotaxy syndrome. However, the exact aetiology of CHD and heterotaxy syndrome remains unclear. In this study, targeted sequencing and Sanger sequencing were performed to analyze the exonic regions of 37 primary ciliary dysfunction (PCD)- related candidate genes in 42 CHD patients with heterotaxy syndrome. Variants affecting protein-coding regions were filtered according to databases of known variants and predicted in silico using functional prediction program. Thirty-four potential disease-causing heterozygous variants in 11 genes were identified in the 19 CHD patients with heterotaxy syndrome (45.2%, 19/42). The DNAH11 gene showed the highest mutation rate (16.7%; 14 of 84 alleles) among the CHD patients with heterotaxy. Fisher's exact test revealed a significant association of DNAH11 variants with CHD and heterotaxy (P = 0.0001). In families, six different compound heterozygous variants of DNAH11 were validated in family 1-5031 (p.W802X/p.M282I), family 2-5045 (p.T3460K/p.G4425S), family 3-5065 (p.G447R/p.L1157R), family 4-5130 (p.I2262T/p.D3800H), family 5-5707 (p.S1823fs/p.F2759L/p.R4395X) and family 6-5062 (p.D3610V/p.I243V). These findings suggest that the DNAH11 variants are significantly associated with CHD and heterotaxy syndrome and that compound heterozygous DNAH11 variants may be the common genetic cause of the development of familial CHD and heterotaxy syndrome.