Defining α-skeletal and α-cardiac actin expression in human heart and skeletal muscle explains the absence of cardiac involvement in ACTA1 nemaline myopathy

Abstract

Mutations in α-skeletal actin (ACTA1) underlie several congenital muscle disorders including nemaline myopathy (NM). Almost all ACTA1-NM patients have normal cardiac function, and, even lethally affected congenital NM patients exhibit an unremarkable gestation with decreased foetal movement just prior to birth. Although α-skeletal actin is thought to be the predominant sarcomeric actin in human heart (Boheler KR, Carrier L, de la Bastie D, et al. Skeletal actin mRNA increases in the human heart during ontogenic development and is the major isoform of control and failing adult hearts. J Clin Invest 1991;88:323-30 [1]), ACTA1-NM patients almost never exhibit a cardiac phenotype. In this study,..