title: MELAS phenotype associated with m.3302A>G mutation in mitochondrial tRNA(Leu(UUR)) gene.
abstract: The m.3302A>G mutation in the mitochondrial tRNA(Leu(UUR)) gene has been identified in only 12 patients from 6 families, all manifesting adult-onset slowly progressive myopathy with minor central nervous system involvement. An 11-year-old boy presented with progressive proximal-dominant muscle weakness from age 7years. At age 10, he developed recurrent stroke-like episodes. Mitochondrial myopathy, encephalopathy, lactic acidosis, plus stroke-like episodes (MELAS) was diagnosed by clinical symptoms and muscle biopsy findings. Mitochondrial gene analysis revealed a heteroplasmic m.3302A>G mutation. Histological examination showed strongly SDH reactive blood vessels (SSVs), not present in previous cases with myopathies due to the m.3302A>G mutation. These findings broaden the phenotypic spectrum of this mutation.
authors.affiliation: Department of Child Neurology, National Center Hospital, National Center of Neurology and Psychiatry, Tokyo, Japan.
authors.forename: Masahide
authors.initials: M
authors.lastname: Goto
authors.affiliation: Department of Child Neurology, National Center Hospital, National Center of Neurology and Psychiatry, Tokyo, Japan. Electronic address: komakih@ncnp.go.jp.
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Komaki
authors.affiliation: Department of Child Neurology, National Center Hospital, National Center of Neurology and Psychiatry, Tokyo, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Saito
authors.affiliation: Department of Child Neurology, National Center Hospital, National Center of Neurology and Psychiatry, Tokyo, Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Saito
authors.affiliation: Department of Child Neurology, National Center Hospital, National Center of Neurology and Psychiatry, Tokyo, Japan.
authors.forename: Eiji
authors.initials: E
authors.lastname: Nakagawa
authors.affiliation: Department of Child Neurology, National Center Hospital, National Center of Neurology and Psychiatry, Tokyo, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Sugai
authors.affiliation: Department of Child Neurology, National Center Hospital, National Center of Neurology and Psychiatry, Tokyo, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Sasaki
authors.affiliation: Department of Neuromuscular Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, Japan.
authors.forename: Ichizo
authors.initials: I
authors.lastname: Nishino
authors.affiliation: Department of Mental Retardation and Birth Defect Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, Japan.
authors.forename: Yu-Ichi
authors.initials: Y
authors.lastname: Goto
mesh_terms: D002648:Child; D006801:Humans; D017241:MELAS Syndrome / Q000175:diagnosis / Q000235:genetics*; D008297:Male; D008928:Mitochondria / Q000235:genetics*; D009154:Mutation / Q000235:genetics; D010641:Phenotype; D012356:RNA, Transfer, Leu / Q000235:genetics*
chemical_list: D012356:RNA, Transfer, Leu
keywords: MELAS; Myopathy; m.3302A>G mutation