MICA polymorphism is associated with type 1 diabetes in the Korean population.
OBJECTIVE
Recent studies have demonstrated that MICA (major histocompatibility complex class I chain-related genes) on the short arm of the chromosome 6 are associated with susceptibility to various autoimmune diseases in Caucasians. The aim of our study was to investigate the role of MICA in type 1 diabetes susceptibility independent of the HLA DR-DQ polymorphism in genetically distinct Koreans.


METHODS
A total of 119 patients selected from Korean Seoul type 1 diabetes registry and 134 nondiabetic unrelated control subjects were typed for exon 5 polymorphism of MICA in addition to HLA DR-DQ typing. A total of 52 simplex families of type 1 diabetes were also studied.


RESULTS
The MICA microsatellite allele consisting of six repetitions of GCT/AGC (A6) was present at a significantly lower frequency in the diabetic patient group (Pc < 0.01; Pc = P value after Bonferroni correction) than in the control population. The MICA microsatellite allele consisting of four repetitions (A4) was present at a higher frequency in diabetic patients (P < 0.05). This deviated distribution was not changed even after controlling for the HLA DRB1-DQB1 haplotype. Transmission/disequilibrium test revealed significant deviation of transmission for alleles at the A6 polymorphism within the MICA gene (P < 0.05).


CONCLUSIONS
We could assess that the MICA gene might be associated with type 1 diabetes transracially independent of the HLA gene.
Park
Y
Y
Department of Internal Medicine, Hanyang and Seoul National University, School of Medicine, Korea.
Lee
H
H
Sanjeevi
C B
CB
Eisenbarth
G S
GS
D000293:Adolescent; D000328:Adult; D000483:Alleles; D002648:Child; D002675:Child, Preschool; D003922:Diabetes Mellitus, Type 1 / Q000235:genetics*; D005787:Gene Frequency; D005805:Genes, MHC Class I / Q000235:genetics*; D005802:Genes, MHC Class II / Q000235:genetics; D005838:Genotype; D006239:Haplotypes; D006801:Humans; D007723:Korea; D015810:Linkage Disequilibrium; D018895:Microsatellite Repeats; D008875:Middle Aged; D011110:Polymorphism, Genetic