Atypical MELAS associated with mitochondrial tRNA(Lys) gene A8296G mutation.
We report on a unique patient with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) presenting optic atrophy, cardiomyopathy, and bilateral striatal necrosis before stoke-like episodes became apparent. Skeletal muscle total mitochondrial DNA analysis identified a heteroplasmic A to G point mutation in the tRNA(Lys) gene at position 8296. Skeletal muscle pathology revealed typical MELAS findings, including ragged-red fibers cytochrome c oxidase positive strongly succinate dehydrogenase-reactive blood vessels. Recent reports describe the 8296 mutation identified in patients with diabetes mellitus or myoclonus epilepsy with ragged-red fibers, not MELAS. We conclude that the 8296 mutation is likely to be pathogenic and that it may be not only a mutation responsible for diabetes mellitus or myoclonus epilepsy with ragged-red fibers but also for MELAS.
Sakuta
Ryoichi
R
Department of Pediatrics, Koshigaya Hospital, Dokkyo University School of Medicine, Saitama, Japan.
Honzawa
Shiho
S
Murakami
Nobuyuki
N
Goto
Yuichi
Y
Nagai
Toshiro
T
D000293:Adolescent; D001706:Biopsy; D009202:Cardiomyopathies / Q000175:diagnosis / Q000209:etiology; D003342:Corpus Striatum / Q000473:pathology; D004252:DNA Mutational Analysis; D004272:DNA, Mitochondrial / Q000235:genetics*; D004452:Echocardiography; D006801:Humans; D017241:MELAS Syndrome / Q000175:diagnosis* / Q000235:genetics* / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D018656:Muscle Fibers, Fast-Twitch / Q000473:pathology; D018482:Muscle, Skeletal / Q000098:blood supply / Q000473:pathology; D009896:Optic Atrophy / Q000175:diagnosis / Q000209:etiology; D017354:Point Mutation / Q000235:genetics*; D012357:RNA, Transfer, Lys / Q000235:genetics*
D004272:DNA, Mitochondrial; D012357:RNA, Transfer, Lys