[Detection of the CAG trinucleotide repeats of MJD1 gene by recombinant DNA technology].
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.
Zhang
Shen
S
Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, 410008 P.R. China.
Wang
Jun-ling
JL
Xu
Qian
Q
Li
Xiao-hui
XH
Lei
Li-fang
LF
Jiang
Hong
H
Shen
Lu
L
Yan
Xin-xiang
XX
Pan
Qian
Q
Xia
Kun
K
Tang
Bei-sha
BS
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
D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins; D012097:Repressor Proteins; C092341:ATXN3 protein, human; D000067699:Ataxin-3