This article describes 2 mitochondrial DNA mutations in the ND3 and ND5 genes in patients showing clinical features of mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS)/Leigh syndrome overlap syndrome and atypical Leigh syndrome.
Here, from the sequencing of the entire mitochondrial genome, we report a Korean MELAS family harboring two homoplasmic missense mutations, which were reported 9957T>C (Phe251Leu) transition mutation in the cytochrome c oxidase subunit 3 (COX3) gene and a novel 13849A>C (Asn505His) transversion mutation in the NADH dehydrogenase subunit 5 (ND5) gene.
This is the 15th mutation affecting the MTND5 subunit of respiratory chain complex I and confirms this protein as an important site for disease with phenotypes ranging from MELAS and infantile encephalopathies to isolated syndromes affecting a single tissue such as Leber hereditary optic neuropathy and now skeletal muscle.
Our observations add to the evidence that mitochondrial ND5 protein coding gene mutations frequently associate with the MELAS phenotype, and it highlights the role of complex I dysfunction in MELAS.
Our observations add to the evidence that mitochondrial ND5 protein coding gene mutations frequently associate with the MELAS phenotype, and it highlights the role of complex I dysfunction in MELAS.
We report a novel G13513A mutation in the mitochondrial ND5 gene in a patient who had morphologically and biochemically abnormal muscle mitochondria and died at age 45 with a diagnosis of MELAS (mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes).
Here we report the first heteroplasmic mitochondrial DNA (mtDNA) point mutation (3376G>A) in the MTND1 gene associated with an overlap syndrome comprising the clinical features of both LHON and MELAS.