Some variants involved in mitochondrial translation machinery genes recently have been reported to cause myocardial hypertrophy.31 For instance, deficiency of GTPBP3 or MTO1 causes myocardial hypertrophy by disrupting mitochondrial biogenesis and RNA maturation in zebrafish.32,33 The variant of the mitochondrial 16S ribosomal RNA gene (MT-RNR2) results in mitochondrial dysfunctions and ultrastructure defects, causing HCM.34 Several variants of mtARS (eg, AARS2, VARS2, and YARS2) have been identified to cause HCM in humans by mitochondrial deficiency. Here, MTO1 is linked to cardiac hypertrophy.