Genetics of type 1 diabetes: similarities and differences between Asian and Caucasian populations.
Transracial studies are a powerful tool for genetic association studies of multifactorial diseases, such as type 1 diabetes. We therefore studied the association of candidate genes, HLA, INS, CTLA4, PTPN22, and SUMO4, with type 1 diabetes in Asian populations in comparison with Caucasian populations. Class II HLA was strongly associated with type 1 diabetes in both Asian and Caucasian populations, but alleles associated with type 1 diabetes are different among different ethnic groups due to difference in allele distribution in general populations. INS was associated with type 1 diabetes in both Japanese and Caucasian populations, but frequency of disease-associated haplotype was markedly higher in Japanese than in Caucasian populations. CTLA4 association was reported for both type 1 diabetes and autoimmune thyroid diseases (AITD) in Caucasian populations, but the association with type 1 diabetes was concentrated in a subset of patients with AITD in Japanese. A variant (R620W) of PTPN22 was consistently associated with type 1 diabetes in Caucasian populations, but the variant was absent in Asian populations including Japanese. M55V variant of SUMO4 was significantly associated with type 1 diabetes in Asians, but genetic heterogeneity between Asian and Caucasian populations was suggested. These data indicate the importance of transracial studies with a large number of samples in each ethnic group in genetic dissection of type 1 diabetes.
Ikegami
Hiroshi
H
Department of Endocrinology, Metabolism and Diabetes, Kinki University School of Medicine, 377-2 Ohno-higashi, Osaka-sayama, Osaka 589-8511, Japan. ikegami@med.kindai.ac.jp
Fujisawa
Tomomi
T
Kawabata
Yumiko
Y
Noso
Shinsuke
S
Ogihara
Toshio
T
D000483:Alleles; D044466:Asian People / Q000235:genetics*; D001327:Autoimmune Diseases / Q000235:genetics*; D003922:Diabetes Mellitus, Type 1 / Q000235:genetics* / Q000276:immunology; D005787:Gene Frequency; D018740:Genetic Heterogeneity; D006239:Haplotypes; D000949:Histocompatibility Antigens Class II / Q000235:genetics; D006801:Humans; D007564:Japan / Q000453:epidemiology; D011153:Population / Q000235:genetics*; D025841:Small Ubiquitin-Related Modifier Proteins / Q000235:genetics; D013967:Thyroiditis, Autoimmune / Q000235:genetics; D044465:White People / Q000235:genetics*
D000949:Histocompatibility Antigens Class II; D025841:Small Ubiquitin-Related Modifier Proteins