Clinical and genetic spectrum of mitochondrial DNA depletion syndromes: A report of 6 cases with 4 novel variants.

Unlabelled: Mitochondrial DNA (mtDNA) depletion syndromes (MDS) are a heterogeneous group of rare autosomal recessive genetic disorders characterized by a decrease in the number of mtDNA copies inside the organ involved. There are three distinct forms of MDS including the hepatocerebral, the myopathic and the encephalomyopathic forms. The diversity in the clinical and genetic spectrum of these disorders makes the diagnosis challenging.