DNAH11 compound heterozygous variants cause heterotaxy and congenital heart disease

Abstract

Heterotaxy (HTX), a condition characterized by internal organs not being arranged as expected relative to each other and to the left-right axis, is often accompanied with congenital heart disease (CHD). The purpose was to detect the pathogenic variants in a Chinese family with HTX and CHD. A non-consanguineous Han Chinese family with HTX and CHD, and 200 unrelated healthy subjects were enlisted. Exome sequencing and Sanger sequencing were applied to identify the genetic basis of the HTX family. Compound heterozygous variants, c.3426-1G>A and c.4306C>T (p.(Arg1436Trp)), in the dynein axonemal heavy chain 11 gene (DNAH11) were identified in the proband via exome sequencing and further confirmed by Sanger sequencing. Neither c.3426-1G>A nor c.4306C>T variant in the DNAH11 gene was detected in 200 healthy controls. The DNAH11 c.3426-1G>A variant was predicted as altering the acceptor splice site and most likely affecting splicing. The DNAH11 c.4306C>T variant was predicted to be damaging, which may reduce the phenotype severity. The compound heterozygous variants, c.3426-1G>A and c.4306C>T, in the DNAH11 gene might be the pathogenic alterations resulting in HTX and CHD in this family. These findings broaden the variant spectrum of the DNAH11 gene and increase knowledge used in genetic counseling for the HTX family.

Fig 1. Pedigree of a Chinese heterotaxy family, chest X-ray of the heterotaxy patient and the DNAH11 Sanger sequencing electropherograms.

(A) Pedigree of a Chinese heterotaxy family. N, normal; V1, the DNAH11 c.3426-1G>A variant; V2, the DNAH11 c.4306C>T variant. The slash indicates deceased individual, the fully shaded symbol indicates the affected individual, and the arrow indicates the proband. (B) Chest X-ray of the family member (II:2) revealed dextrocardia. (C, D) The compound heterozygosity for the DNAH11 variants, c.3426-1G>A and c.4306C>T, in the individual (II:2) with heterotaxy.

Fig 2. Structural modeling displayed conformational changes of the DNAH11 p.(Arg1436Trp) variant.

(A) The cartoon representation of the DNAH11 protein. (B) The stick model of the arginine at residue 1436 (p.Arg1436). (C) The stick model of the mutant tryptophan at residue 1436 (p.Trp1436).