MIEF2 and Mitochondrial myopathy: Scarpelli et al. (2018) report two mtDNA mutations in mitochondrial myopathy patients. Specifically, the paper identifies the m.8305C>T mutation in the MTTK gene and the MTTM gene m.4440G>A mutation (Scarpelli et al., 2018). The authors conclude that mutations in mitochondrial tRNAs represent hot spots for mitochondrial myopathies in adults. Another recent paper by Bartsakoulia et al. (2018) identifies mutations in MIEF2 gene that results in imbalanced mitochondrial dynamics and a combined respiratory chain enzyme defect in skeletal muscle, leading to mitochondrial myopathy.