Association of MICA polymorphism with HLA-B51 and disease severity in Korean patients with Behcet's disease.
The HLA-B51 allele is known to be associated with Behcet's disease (BD) in many ethnic group. However, it has not yet been clarified whether the HLA-B51 gene itself is the pathogenic gene related to BD or whether it is some other gene in linkage disequlibrium with HLA-B51. Recently, the Triplet repeat (GCT/AGC) polymorphism in transmembrane region of the MHC class I chain-related A (MICA) gene was identified. To investigate the association of MICA with BD, we studied the MICA polymorphism in 108 Korean BD patients and 204 healthy controls in relation to the presence of HLA-B51 and clinical manifestations. The triplet repeat polymorphism was determined by polymerase chain reaction (PCR)-denaturing polyacrylamide gel electrophoresis (PAGE). The phenotype frequency of the MICA*A6 allele (relative risk, RR=2.15, p=0.002) and HLA-B51(RR=1.87, p=0.022) were significantly increased in the Korean patients with BD. A strong linkage disequilibrium was observed between the MICA*A6 and HLA-B51 in both the patients with BD and control subjects. Stratification analysis showed that MICA*A6 homozygosity was strongly associated with BD in the HLA-B51-negative population, and HLA-B51 was also associated with MICA*A6-negative population. In conclusion, MICA*A6 rather than HLA-B51 was strongly associated with Korean patients with BD, and the MICA*A6 allele is a useful susceptibility marker of BD, especially in the HLA-B5-negative
Park
Sung-Hwan
SH
Center for Rheumatic Diseases, Kangnam St.Mary's Hospital, The Catholic University of Korea, Seoul, Korea.
Park
Kyung-Su
KS
Seo
Young-Il
YI
Min
Do-June
DJ
Kim
Wan-Uk
WU
Kim
Tai-Gyu
TG
Cho
Chul-Soo
CS
Mok
Jee-Won
JW
Park
Kyung-Sook
KS
Kim
Ho-Youn
HY
D000328:Adult; D001528:Behcet Syndrome / Q000235:genetics*; D020022:Genetic Predisposition to Disease; D015235:HLA-B Antigens / Q000235:genetics*; D059949:HLA-B51 Antigen; D015395:Histocompatibility Antigens Class I / Q000235:genetics*; D006801:Humans; D007723:Korea; D018895:Microsatellite Repeats; D008875:Middle Aged; D010641:Phenotype; D011110:Polymorphism, Genetic; D012720:Severity of Illness Index
D015235:HLA-B Antigens; D059949:HLA-B51 Antigen; D015395:Histocompatibility Antigens Class I; C099187:MHC class I-related chain A