Cardiomyopathy caused by mitochondrial DNA 4300A > G variant.

Abstract

A recent study has shown that a homoplasmic pathogenic variant in mitochondrial deoxyribonucleic acid (mtDNA) m.4300A > G causes isolated cardiac disease in 0.6% of patients with gene elusive hypertrophic cardiomyopathy (HCM). Here, we describe five families with the m.4300A > G mtDNA variant and demonstrate a cardiac phenotype associated with sudden cardiac death (SCD) in relatives, extensive fibrosis, myocardial inflammation and progressive remodelling to left ventricular (LV) dilation and systolic dysfunction.