title: Elevated urinary β2 microglobulin in the first identified Japanese family afflicted by X-linked myopathy with excessive autophagy.
abstract: Here we report what is to our knowledge the first identified Japanese family afflicted by X-linked myopathy with excessive autophagy. The index case is a 52-year-old man with almost 40years of progressive proximal muscle weakness. High urinary β2 microglobulin, normal serum β2 microglobulin, autophagic vacuoles with sarcolemmal features, and a hemizygous c.164-7T>G mutation in the VMA21 gene were found. His two maternal uncles had similar clinicopathological findings. High urinary β2 microglobulin without obvious renal dysfunction might result from decreased urine acidification in the distal convoluted tubules caused by the VMA21 gene mutation. These findings might prove to be useful as a preliminary marker suggestive of X-linked myopathy with excessive autophagy.
authors.affiliation: Department of Clinical Neuroscience and Therapeutics, Hiroshima University, Graduate School of Biomedical and Health Sciences, Hiroshima, Japan. Electronic address: takashi-kurashige@hiroshima-u.ac.jp.
authors.forename: Takashi
authors.initials: T
authors.lastname: Kurashige
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Takahashi
authors.forename: Yu
authors.initials: Y
authors.lastname: Yamazaki
authors.forename: Yoshito
authors.initials: Y
authors.lastname: Nagano
authors.forename: Keita
authors.initials: K
authors.lastname: Kondo
authors.forename: Takeshi
authors.initials: T
authors.lastname: Nakamura
authors.forename: Takemori
authors.initials: T
authors.lastname: Yamawaki
authors.forename: Rie
authors.initials: R
authors.lastname: Tsuburaya
authors.forename: Yukiko K
authors.initials: YK
authors.lastname: Hayashi
authors.forename: Ikuya
authors.initials: I
authors.lastname: Nonaka
authors.forename: Ichizo
authors.initials: I
authors.lastname: Nishino
authors.forename: Masayasu
authors.initials: M
authors.lastname: Matsumoto
mesh_terms: D000328:Adult; D044466:Asian People; D040181:Genetic Diseases, X-Linked / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D018485:Muscle Fibers, Skeletal / Q000648:ultrastructure; D009135:Muscular Diseases / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology; D009154:Mutation; D025262:Vacuolar Proton-Translocating ATPases / Q000235:genetics*; D001613:beta 2-Microglobulin / Q000097:blood / Q000652:urine*
chemical_list: D001613:beta 2-Microglobulin; C540401:VMA21 protein, human; D025262:Vacuolar Proton-Translocating ATPases
keywords: Autophagic vacuole with sarcolemmal features (AVSF); VMA21; X-linked myopathy with excessive autophagy (XMEA); β2 Microglobulin