[Disequilibrium linkage between the polymorphism in exons 2, 3 and 4 of the MICA gene and HLA-B antigen of patient with ankylosing spondylitis].
OBJECTIVE
To investigate the association between the exons 2 to 4 of the MICA gene and ankylosing spondylitis (AS).


METHODS
By PCR-SSOP, DNA samples from 56 AS patients and 112 random healthy individuals, as normal control were genotyped to analyse the polymorphism in exons 2, 3, 4 of the MICA alleles.


RESULTS
MICA*008 was dominant in MICA allele,accounted for 32.14% and 30.36% in AS patients and normal controls respectively. The frequency of MICA*007 was significantly increased in AS patients, when compared with normal controls (chi-square=10.18, P<0.05, RR=2.50). No difference was found in the other MICA alleles. The haplotype analysis revealed that there were the strong linkage disequilibrium between MICA and HLA-B of AS patients, and normal controls. There was a difference in MICA*007-B27 between two groups (chi-square=18.46, P<0.05, RR=7.47). Both HLA-B27 and MICA*007 were strongly associated with AS. Stratified analysis showed that HLA-B27 was significantly relative to AS,while it was not found between MICA*007 and AS.


CONCLUSIONS
The increased frequency of MICA alleles may be due to its strong linkage disequilibrium with HLA-B27.
Su
Hong
H
Department of Epidemiology and Statistics, Anhui Medical University, Hefei, Anhui 230032, P. R. China.
Wang
Bao-long
BL
Zhang
Xiu-jun
XJ
Hao
Jia-hu
JH
Xiao
Qin
Q
Ye
Dong-qing
DQ
D000483:Alleles; D005091:Exons / Q000235:genetics*; D005787:Gene Frequency; D005838:Genotype; D015235:HLA-B Antigens / Q000235:genetics*; D015796:HLA-B27 Antigen / Q000235:genetics; D015395:Histocompatibility Antigens Class I / Q000235:genetics*; D006801:Humans; D015810:Linkage Disequilibrium / Q000235:genetics*; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic / Q000235:genetics*; D013167:Spondylitis, Ankylosing / Q000235:genetics*
D015235:HLA-B Antigens; D015796:HLA-B27 Antigen; D015395:Histocompatibility Antigens Class I; C099187:MHC class I-related chain A