title: [Detection of the CAG trinucleotide repeats of MJD1 gene by recombinant DNA technology].
abstract: OBJECTIVE
  To establish a stable, accurate and intuitive method for detecting the CAG trinucleotide repeats of MJD1 gene.
  
  
  METHODS
  The CAG trinucleotide polymorphism of the MJD1 gene was analyzed by recombinant DNA technology and DNA sequencing in 35 spinocerebellar ataxia 3/Machado-Joseph disease (SCA3/MJD) patients from Mainland China.
  
  
  RESULTS
  The range of the CAG repeat of the 35 patients was 65-81 (mean = 72.96 +/- 4.24). The CAG repeats contained two CAAs and one AAG variations in the CAG motif in all the patients and majority of the healthy controls. There was a CGG/GGG polymorphism at the 3' end of the CAG repeat. The GGG allele was consistently associated with smaller CAG repeats in healthy controls. On the other hand, the CGG allele consistently existed in the patients.
  
  
  CONCLUSIONS
  Recombinant DNA technology can stably, accurately and intuitively detect the CAG trinucleotide repeat of the MJD1 gene. It should be used as a major technique to diagnose the SCA3/MJD and analyze the polymorphism of CAG sequence.
authors.affiliation: Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, 410008 P.R. China.
authors.forename: Shen
authors.initials: S
authors.lastname: Zhang
authors.forename: Jun-ling
authors.initials: JL
authors.lastname: Wang
authors.forename: Qian
authors.initials: Q
authors.lastname: Xu
authors.forename: Xiao-hui
authors.initials: XH
authors.lastname: Li
authors.forename: Li-fang
authors.initials: LF
authors.lastname: Lei
authors.forename: Hong
authors.initials: H
authors.lastname: Jiang
authors.forename: Lu
authors.initials: L
authors.lastname: Shen
authors.forename: Xin-xiang
authors.initials: XX
authors.lastname: Yan
authors.forename: Qian
authors.initials: Q
authors.lastname: Pan
authors.forename: Kun
authors.initials: K
authors.lastname: Xia
authors.forename: Bei-sha
authors.initials: BS
authors.lastname: Tang
mesh_terms: D000293:Adolescent; D000328:Adult; D000067699:Ataxin-3; D001483:Base Sequence; D005260:Female; D005818:Genetic Engineering / Q000379:methods*; D006801:Humans; D017827:Machado-Joseph Disease / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000235:genetics*; D009687:Nuclear Proteins / Q000235:genetics*; D011110:Polymorphism, Genetic; D012097:Repressor Proteins / Q000235:genetics*; D017422:Sequence Analysis, DNA; D018911:Trinucleotide Repeats; D055815:Young Adult
chemical_list: D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins; D012097:Repressor Proteins; C092341:ATXN3 protein, human; D000067699:Ataxin-3