MICA Polymorphism Is Associated With Type 1 Diabetes in the Korean Population
- Yongsoo Park, MD,
- Hongkyu Lee, MD,
- Carani B. Sanjeevi, MD and
- George S. Eisenbarth, MD, PHD
- From the Department of Internal Medicine (Y.P., H.L.), Hanyang and Seoul National University, School of Medicine, Seoul, Korea; the Department of Molecular Medicine (C.B.S.), Karolinska Hospital, Stockholm, Sweden; and the Barbara Davis Center for Childhood Diabetes (G.S.E.), University of Colorado Health Sciences Center, Denver, Colorado.
- Address correspondence and reprint requests to Yongsoo Park, MD, Department of Internal Medicine, Hanyang University Hospital, 249-1 Kyomun-dong, Kuri, Kyunggi-do, 471-020, Korea. E-mail: parkys{at}email.hanyang.ac.kr .
Abstract
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.
RESEARCH DESIGN AND 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.
Footnotes
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Abbreviations: LD, linkage disequilibrium; MHC, major histocompatibility complex; MICA, MHC class I chain-related genes; PCR, polymerase chain reaction; RR, relative risk; TDT, transmission/disequilibrium test.
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- Accepted September 21, 2000.
- Received June 13, 2000.
- by the American Diabetes Association, Inc.
