title: [Mutation analysis of a Chinese family with spinocerebellar ataxia 7].
abstract: OBJECTIVE
  To characterize the clinical phenotype and the gene mutation of the spinocerebellar ataxia 7 (SCA7) family.
  
  
  METHODS
  Two patients from a two generation Hui Chinese pedigree were detected by gene test. Polymerase chain reaction (PCR) for CAG trinucleotide repeats was performed for the SCA7 gene, and the fragments with expanded alleles were subcloned into the pGEM-T plasmids and sequenced.
  
  
  RESULTS
  Molecular analysis demonstrated the pathological expansions in the SCA7 gene, with 46 CAG repeats in the expanded allele of the proband's father. The 46 repeats expanded to 54 repeats in the proband with marked anticipation of approximately 22 years.
  
  
  CONCLUSIONS
  This family was the first SCA7 Hui Chinese family reported. Retinal degeneration is relatively unique to SCA7. The instability of the expanded triplet repeats accounts for the marked anticipation and the rate of progression of the disease.
authors.affiliation: Department of Neurology, the First Teaching Hospital, Xinjiang Medical University, Urumqi, Xinjiang, P.R. China.
authors.forename: Jia
authors.initials: J
authors.lastname: Yu
authors.forename: Jian-hua
authors.initials: JH
authors.lastname: Ma
authors.forename: Jing
authors.initials: J
authors.lastname: Lei
authors.forename: Hai-tao
authors.initials: HT
authors.lastname: Li
authors.forename: Xiao-ning
authors.initials: XN
authors.lastname: Zhang
mesh_terms: D000328:Adult; D044466:Asian People / Q000235:genetics*; D001483:Base Sequence; D004252:DNA Mutational Analysis / Q000379:methods*; D005260:Female; D005787:Gene Frequency; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics*; D010375:Pedigree; D020754:Spinocerebellar Ataxias / Q000235:genetics*; D055815:Young Adult