Replication study for the association between four Loci identified by a genome-wide association study on European American subjects with type 1 diabetes and susceptibility to diabetic nephropathy in Japanese subjects with type 2 diabetes.

Abstract

Genetic factors are believed to contribute to the development and progression of diabetic nephropathy. Recently, a genome-wide association study for diabetic nephropathy revealed four novel candidate loci in European American subjects with type 1 diabetes. In this study, we determined the association of the four loci with diabetic nephropathy in Japanese subjects with type 2 diabetes. We genotyped 11 singlenucleotide polymorphisms (SNPs) in four distinct loci (rs39059 and rs39075 in the CPVL/CHN2, rs1888747 and rs10868025 in FRMD3, rs739401 and rs451041 in CARS, and rs1041466, rs1411766, rs6492208, rs7989848, and rs9521445 in a chromosome 13q locus) in four independent Japanese populations. Six SNPs were nominally associated with diabetic nephropathy in one of the four Japanese populations (P < 0.05; rs451041 in study 1; rs39059 and rs1888747 in study 3; rs1411766 in studies 1 and 4; and rs7989848 and rs9521445 in study 4); however, no significant association was observed for any SNP after correction for multiple testing errors in the individual populations. Nevertheless, a meta-analysis performed for the data obtained from all four populations revealed that one SNP (rs1411766) in chromosome 13q was significantly associated with diabetic nephropathy in the Japanese populations (nominal P = 0.004, corrected P = 0.04, odds ratio 1.26 [95% CI = 1.07-1.47]). Our results suggest that the rs1411766 locus may be commonly involved in conferring susceptibility to diabetic nephropathy among subjects with type 1 or type 2 diabetes across different ethnic groups.