Progressive carotid artery stenosis with a novel tRNA phenylalanine mitochondrial DNA mutation.
Mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS) is a distinct clinical syndrome caused by mutations in the mitochondrial DNA. The pathogenesis of stroke-like episodes remains unknown but major vessels stenosis is not a cause of stroke-like episodes. We describe a novel heteroplasmic G617A transition in the mitochondrial transfer RNA phenylalanine gene in a patient with encephalomyopathy who presented with recurrent embolic ischemic strokes accompanied by transient occlusion of middle cerebral, anterior cerebral and internal carotid arteries. These ischemic strokes were presumed to be artery-to artery embolisms associated with carotid artery stenosis. Single muscle fiber analysis revealed the pathogenicity of the mutation although its causative role on carotid artery stenosis remains to be elucidated. This case expands phenotypic spectrum of mitochondrial disorders in terms of macroangiopathy, but macroangiopathy-related ischemic strokes should be distinguished from classic stroke-like episodes of MELAS that are speculated to be microangioapthy-related or non-ischemic neurovascular events.
Iizuka
Takahiro
T
Department of Neurology, School of Medicine, Kitasato University, Kanagawa, Japan. takahiro@med.kitasato-u.ac.jp
Goto
Yu-ichi
Y
Miyakawa
Saori
S
Sato
Mayumi
M
Wang
Zhaoxia
Z
Suzuki
Kosuke
K
Hamada
Junichi
J
Kurata
Akira
A
Sakai
Fumihiko
F
D000328:Adult; D001921:Brain / Q000473:pathology; D002339:Carotid Arteries / Q000000981:diagnostic imaging; D016893:Carotid Stenosis / Q000235:genetics* / Q000473:pathology; D002533:Cerebral Angiography; D004252:DNA Mutational Analysis; D004272:DNA, Mitochondrial / Q000235:genetics*; D050259:Genes, Mitochondrial; D006801:Humans; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging; D008297:Male; D017237:Mitochondrial Encephalomyopathies / Q000235:genetics* / Q000473:pathology; D018482:Muscle, Skeletal / Q000473:pathology; D020125:Mutation, Missense; D009690:Nucleic Acid Conformation; D012360:RNA, Transfer, Phe / Q000737:chemistry / Q000235:genetics*; D020521:Stroke / Q000235:genetics / Q000473:pathology
D004272:DNA, Mitochondrial; D012360:RNA, Transfer, Phe