obsolete metabolic disorder with intestinal involvement mitochondrial oxidative phosphorylation disorder mitochondrial DNA depletion syndrome https://www.malacards.org/card/mitochondrial_dna_depletion_syndrome Orphanet:35698 OMIMPS:603041 MONDO:0018158 DOID:0070329 GARD:0013643 icd11.foundation:1159345506 UMLS:C0342782 NANDO:2200528 MedDRA:10059396 mtDNA depletion syndrome MEDGEN:452449 The mitochondrial DNA (mtDNA) depletion syndrome (MDS) is a clinically heterogeneous group of mitochondrial disorders characterized by a reduction of the mtDNA copy number in affected tissues without mutations or rearrangements in the mtDNA. MDS is phenotypically heterogeneous, and can affect a specific organ or a combination of organs, with the main presentations described being either hepatocerebral (i.e. hepatic dysfunction, psychomotor delay), myopathic (i.e. hypotonia, muscle weakness, bulbar weakness), encephalomyopathic (i.e. hypotonia, muscle weakness, psychomotor delay) or neurogastrointestinal (i.e gastrointestinal dysmotility, peripheral neuropathy). Additional phenotypes include fatal infantile lactic acidosis with methylmalonic aciduria, spastic ataxia (early-onset spastic ataxia-neuropathy syndrome), and Alpers syndrome. NANDO:2200523