Is the mitochondrial complex I ND5 gene a hot-spot for MELAS causing mutations?
We identified two novel heteroplasmic mitochondrial DNA point mutations in the gene encoding the ND5 subunit of complex I: a 12770A-->G transition identified in a patient with MELAS (mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes) and a 13045A-->C transversion in a patient with a MELAS/Leber's hereditary optic neuropathy/Leigh's overlap syndrome. Biochemical analysis of muscle homogenates showed normal or very mildly reduced complex I activity. Histochemistry was normal. 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.
Liolitsa
Danae
D
Neuromuscular Unit, Institute of Neurology, University College London, United Kingdom.
Rahman
Shamina
S
Benton
Sarah
S
Carr
Lucinda J
LJ
Hanna
Michael G
MG
D000595:Amino Acid Sequence; D002648:Child; D042967:Electron Transport Complex I / Q000235:genetics*; D006801:Humans; D017241:MELAS Syndrome / Q000235:genetics* / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008969:Molecular Sequence Data; D010641:Phenotype; D017354:Point Mutation
D042967:Electron Transport Complex I