Atrophic muscularis propria, Cachexia, Cirrhosis, Constipation, Cytochrome C oxidase-negative muscle fibers, Decreased motor nerve conduction velocity, Decreased muscle mass, Decreased number of large peripheral myelinated nerve fibers, Decreased sensory nerve conduction velocity, Dementia, Demyelinating peripheral neuropathy, Diarrhea, Distal amyotrophy, Distal muscle weakness, Distal sensory impairment, Dysphagia, Easy fatigability, Elevated circulating hepatic transaminase concentration, External ophthalmoplegia, Foot dorsiflexor weakness, Gastroesophageal reflux, Gastrointestinal dysmotility, Gastroparesis, Hyperalaninemia, Hypergonadotropic hypogonadism, Hypogonadotropic hypogonadism, Hypointensity of cerebral white matter on MRI, Increased CSF protein, Intellectual disability, Intermittent diarrhea, Intestinal perforation, Lactic acidosis, Leukoencephalopathy, Macrovesicular hepatic steatosis, Malabsorption, Malnutrition, Mitochondrial myopathy, Multiple mitochondrial DNA deletions, Nausea, Ophthalmoparesis, Paresthesia, Peripheral axonal neuropathy, Peripheral neuropathy, Poor appetite, Progressive external ophthalmoplegia, Ptosis, Ragged-red muscle fibers, Sensorimotor neuropathy, Sensorineural hearing impairment, Slender build, Small intestinal dysmotility, Subsarcolemmal accumulations of abnormally shaped mitochondria, Vomiting, Weight loss