BAG3 and familial dilated cardiomyopathy: The BAG3 p.His166SerfsTer6 mutation was considered the causative variant of DCM because the neighboring frameshift variant BAG3 p.Pro163GlnfsTer48 is defined as pathogenic17, and heterozygous frameshift or stop-gain variants of BAG3 have been identified previously in patients with DCM29,30.