ICD-10-CM > E00-E89 > E70-E88 > E88 > E88.4 E88.4 Mitochondrial metabolism disorders Non-Billable/Non-Specific Type 1 Excludes disorders of pyruvate metabolism (E74.4)Kearns-Sayre syndrome (H49.81)Leber's disease (H47.22)Leigh's encephalopathy (G31.82)Mitochondrial myopathy, NEC (G71.3)Reye's syndrome (G93.7) Codes E88.40Mitochondrial metabolism disorder, unspecifiedE88.41MELAS syndromeE88.42MERRF syndromeE88.43Disorders of mitochondrial tRNA synthetasesE88.49Other mitochondrial metabolism disorders