APOO and Immunodeficiency: On the other hand, deficiency of the Mic26 subunit (APOO, X-linked recessive mitochondrial myopathy, lactic acidosis, cognitive impairment, and autistic features) has been reported to be associated with a variable form of mitochondrial myopathy with lactic acidosis, cognitive impairment and autistic features, or with a lethal mitochondrial disease with a progeria-like phenotype associated with partial agenesis of the corpus callosum, bilateral congenital cataracts, hypothyroidism, and severe immune deficiencies [213].