Mitochondrial Dna Depletion Syndrome 8a, also known as mitochondrial dna depletion syndrome 8b, is related to mitochondrial dna depletion syndrome 4b and visceral myopathy, familial, with external ophthalmoplegia, and has symptoms including cachexia, seizures and gait ataxia. An important gene associated with Mitochondrial Dna Depletion Syndrome 8a is RRM2B (Ribonucleotide Reductase Regulatory TP53 Inducible Subunit M2B), and among its related pathways/superpathways is Energy metabolism. Affiliated tissues include brain and kidney, and related phenotypes are proximal tubulopathy and lactic acidosis