title: Spinocerebellar ataxia type 21 exists in the Chinese Han population.
abstract: Recently, mutations in transmembrane protein 240 (TMEM240) were identified as the cause of spinocerebellar ataxia type 21 (SCA21) in several French families. Clinically, SCA21 is characterized as an early-onset, slowly progressive cerebellar syndrome typically associated with cognitive impairment. To date, molecular screening of SCA21 has not been reported among patients of other ethnic origins or in other areas. Here we used Sanger sequencing to detect mutations in exons of TMEM240 in 340 unrelated probands with spinocerebellar ataxia for whom commonly known causative mutations have been excluded (96 probands of autosomal dominant spinocerebellar ataxia families and 244 patients with sporadic spinocerebellar ataxia). As a result, a de novo missense mutation (c.509C > T/p.P170L) was identified in one sporadic SCA patient. The condition manifested as early-onset (30 years old), slowly progressive cerebellar ataxia accompanied by mild early evidenced mental retardation, mild frontal behavior disorders and intentional hand tremors. Although rare, a SCA21 case was identified and described in mainland China, thus broadening the ethnic distribution of SCA21 beyond French families.
authors.affiliation: Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, P.R. China.
authors.forename: Sheng
authors.initials: S
authors.lastname: Zeng
authors.affiliation: Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, P.R. China.
authors.forename: Junsheng
authors.initials: J
authors.lastname: Zeng
authors.affiliation: Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, P.R. China.
authors.forename: Miao
authors.initials: M
authors.lastname: He
authors.affiliation: Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, P.R. China.
authors.forename: Xianfeng
authors.initials: X
authors.lastname: Zeng
authors.affiliation: Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, P.R. China.
authors.forename: Yao
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, P.R. China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Medical Genetics, Changsha, Hunan, P.R. China.
authors.forename: Kun
authors.initials: K
authors.lastname: Xia
authors.affiliation: State Key Laboratory of Medical Genetics, Changsha, Hunan, P.R. China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Pan
authors.affiliation: Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, P.R. China.|Key Laboratory of Hunan Province in Neurodegenerative Disorders, Changsha, Hunan, P.R. China.|State Key Laboratory of Medical Genetics, Changsha, Hunan, P.R. China.
authors.forename: Hong
authors.initials: H
authors.lastname: Jiang
authors.affiliation: Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, P.R. China.|Key Laboratory of Hunan Province in Neurodegenerative Disorders, Changsha, Hunan, P.R. China.|State Key Laboratory of Medical Genetics, Changsha, Hunan, P.R. China.
authors.forename: Lu
authors.initials: L
authors.lastname: Shen
authors.affiliation: Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, P.R. China.
authors.forename: Xinxiang
authors.initials: X
authors.lastname: Yan
authors.affiliation: Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, P.R. China.|Key Laboratory of Hunan Province in Neurodegenerative Disorders, Changsha, Hunan, P.R. China.|State Key Laboratory of Medical Genetics, Changsha, Hunan, P.R. China.
authors.forename: Beisha
authors.initials: B
authors.lastname: Tang
authors.affiliation: Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, P.R. China.|Key Laboratory of Hunan Province in Neurodegenerative Disorders, Changsha, Hunan, P.R. China.|State Key Laboratory of Medical Genetics, Changsha, Hunan, P.R. China.
authors.forename: Junling
authors.initials: J
authors.lastname: Wang
mesh_terms: D000328:Adult; D044466:Asian People; D002681:China / Q000453:epidemiology; D003071:Cognition; D004252:DNA Mutational Analysis; D005091:Exons; D006801:Humans; D007438:Introns; D008297:Male; D008565:Membrane Proteins / Q000235:genetics; D009043:Motor Activity; D009154:Mutation; D010375:Pedigree; D013132:Spinocerebellar Degenerations / Q000175:diagnosis / Q000453:epidemiology* / Q000235:genetics*
chemical_list: D008565:Membrane Proteins; C000592813:TMEM240 protein, human
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