A novel ZIC3 mutation in a Chinese family with heterotaxy and multiple types of congenital heart defect.

Abstract

A couple was referred for prenatal counseling at gestational age 21weeks for revealed situs inversus with levocardia (HP:0,031,592), atrial situs inversus (HP:0,011,538), congenitally corrected transposition of the great arteries (ccTGA, HP:0,011,540) with ventricular septal defect (HP:0,001,629) and right aortic arch (HP:0,012,020). The couple had multiple prior pregnancies with complex congenital heart defects (CHDs, HP:0,001,627) in male fetuses. Testing was initiated to identify any fetal abnormality. The genetic cause of the observed prenatal defects was investigated. Whole exome sequencing and Sanger sequencing were performed on DNA extracted from parental blood samples and skeletal muscle tissue of the aborted fetuses. A pathogenic hemizygous missense variant in ZIC3 (NM_003413.4: c.895T>C) associated with X-linked heterotaxy-1 (HTX1) and multiple types of congenital heart defect-1 (CHTD1) (OMIM #306955) was identified, which was inherited from the mother. ZIC3 encodes a highly conserved zinc-finger protein that is highly correlated with CHDs. The present study of a Han Chinese family with CHDs expands the mutation spectrum of ZIC3 and provides further evidence that ZIC3 plays important roles in CHDs.