Dual Renal and Cardiac Phenotypes Associated with Rare Variants Inherited from Both Parents

We herein report a woman with autosomal dominant Alport syndrome (ADAS) with a family history of left ventricular noncompaction cardiomyopathy (LVNC). Exome sequencing identified a rare heterozygous variant in COL4A4, NM_000092.5: c.2510G>C (p.G837A), and a novel heterozygous variant in ACTC1, NM_005159.5: c.922T>C (p.Y308H), as causes of ADAS and LVNC, respectively. The cardiac phenotype was presumed to have been inherited paternally, whereas the renal phenotype was assumed to be maternally inherited. These two variants independently contributed to clinical phenotypes. This case highlights the clinical significance of comprehensive genetic testing for facilitating the precise diagnosis of rare and complex hereditary disorders.