TSFM and mitochondrial DNA depletion syndrome, encephalomyopathic form with methylmalonic aciduria: A next-generation sequencing (NGS)-based multigene panel for mitochondrial dysfunction was used to identify a TSFM homozygous variant, c.547G>A, p.Gly183Ser, associated with early onset encephalomyopathy with sensorineural hearing loss and peculiar neuroimaging features.