Novel mitochondrial DNA ND5 mutation in a patient with clinical features of MELAS and MERRF.
BACKGROUND
The mitochondrial DNA gene encoding subunit 5 of complex I (ND5) has turned out to be a hot spot for mutations associated with mitochondrial encephalomyopathy with lactic acidosis and strokelike episodes (MELAS) and various overlap syndromes.


OBJECTIVE
To describe a novel mutation in the ND5 gene in a young man man with an overlap syndrome of MELAS and myoclonus epilepsy with ragged-red fibers.


METHODS
Case report.


METHODS
A 25-year-old man had recurrent strokes, seizures, and myoclonus. His mother also had multiple strokes. A muscle biopsy specimen showed no ragged-red fibers but several strongly succinate dehydrogenase-reactive blood vessels.


RESULTS
Biochemical analysis showed isolated complex I deficiency and molecular analysis revealed a novel heteroplasmic mutation (G13042A) in the ND5 gene.


CONCLUSIONS
These data confirm that ND5 is a genetic hot spot for overlap syndromes, including MELAS and strokelike and myoclonus epilepsy with ragged-red fibers.
Naini
Ali B
AB
Department of Neurology, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA.
Lu
Jiesheng
J
Kaufmann
Petra
P
Bernstein
Richard A
RA
Mancuso
Michelangelo
M
Bonilla
Eduardo
E
Hirano
Michio
M
DiMauro
Salvatore
S
D000328:Adult; D000595:Amino Acid Sequence; D004272:DNA, Mitochondrial / Q000235:genetics*; D042967:Electron Transport Complex I / Q000235:genetics*; D006801:Humans; D017241:MELAS Syndrome / Q000201:enzymology / Q000235:genetics* / Q000473:pathology; D017243:MERRF Syndrome / Q000201:enzymology / Q000235:genetics* / Q000473:pathology; D008297:Male; D024101:Mitochondrial Proteins; D008969:Molecular Sequence Data; D009154:Mutation; D021122:Protein Subunits / Q000235:genetics*; D013385:Succinate Dehydrogenase / Q000235:genetics / Q000378:metabolism
D004272:DNA, Mitochondrial; D024101:Mitochondrial Proteins; D021122:Protein Subunits; D013385:Succinate Dehydrogenase; C481838:MT-ND5 protein, human; D042967:Electron Transport Complex I