This report contains information about diseases included within the OMIM phenotypic series "mitochondrial DNA depletion syndrome" (MDS). mtDNA depletion syndromes are due to defects in mtDNA maintenance caused by nuclear genes that function in either mitochondrial nucleotide synthesis or mtDNA replication. A listing of MDS subtypes can be found in the 'Related Diseases" section below, with links to more detailed reports for subtypes that have been investigated using fly models. A related but less severe disease is progressive external ophthalmoplegia (PEO); see FBhh0000444.
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). [http://www.orpha.net/consor/cgi-bin/OC_Exp.php?Lng=GB&Expert=35698.0 2016.11.23]
mtDNA depletion syndromes are due to defects in mtDNA maintenance caused by nuclear genes that function in either mitochondrial nucleotide synthesis or mtDNA replication (El-Hattab and Scaglia, 2013; pubmed:23385875).
