Monarch Disease Ontology identifier MONDO_0100138 (X-linked recessive mitochondrial myopathy) is a mitochondrial myopathy caused by defects in the MICOS subunit gene APOO (MIC26). Modelling in yeast and flies demonstrate an inability to insert MICOS complex into the inner mitohondrial membrane. Associated symptoms include, lactic acidosis, cognitive impairment and autistic features. Also known as: X-linked recessive mitochondrial myopathy, lactic acidosis, cognitive impairment and autistic features.