A Novel NKX2-5 Variant in a Child with Left Ventricular Noncompaction, Atrial Septal Defect, Atrioventricular Conduction Disorder, and Syncope.

The NKX2-5 gene encodes a transcription factor and is actively involved in heart formation and development. A pediatric case with its variant and left ventricular noncompaction (LVNC) has not been reported. A 12-year-old girl with a history of a surgery for atrial septal detect was referred because of syncope during exercise. The electrocardiogram showed atrioventricular block, and the echocardiogram revealed prominent trabeculations in the left ventricular wall, suggesting LVNC. A novel heterozygous variant in the NKX2-5 gene (NM_004387.1: c.255_256delCT, p.Phe86fs) was identified. NKX2-5 variants should be considered in cases with LVNC, congenital heart disease, arrhythmia, and syncope to prevent sudden cardiac death.