Cardiac involvement is rare in patients with nemaline myopathy, but has been identified in a few patients with defects in ACTA1, MYPN or MYO18B (D’Amico et al. 2006; Kim et al. 2011; Finsterer and Stollberger 2015; Malfatti et al. 2015; Miyatake et al. 2017). The gene discussed is MYPN; the disease is nemaline myopathy.