A rare heteroplasmic point mutation in the MT-ND5 gene (m.13094T>C; p.Val253Ala) found in a patient with adult onset MELAS syndrome: a case report

AbstractBackground:Mitochondrial encephalopathy, lactic acidosis and stroke-like episodes (MELAS) is a rare multisystem mitochondrial cytopathy that is highly heterogeneous in severity and clinical presentation mostly caused by diverse mutations in the mitochondrial DNA. Clinical spectrum of MELAS is broadening as atypical presentations and more knowledge are gathering from this syndrome. There is no specific known treatment for the progressive disease however metabolic cocktail have been used to improve ATP production.Case presentation: This report documents the case of a 37 year old Iranian woman diagnosed with MELAS. Her clinical manifestations include recurrent episodes of stroke-like events, focal seizures and elevated serum and CSF lactate. Mitochondrial DNA analysis (mtDNA) was positive for a very rare pathogen point mutation (mtDNA; m.3243A>G) in the MT-ND5 gene with a heteroplasmy level of 8.2%.Conclusion:The clinical spectrum of MELAS is broadening as its atypical presentations make a diagnostic challenge that may lead to decades of delay in diagnosis. The number of molecular causes of MELAS and Leigh syndrome (LS) has increased steadily.