The Association of Type 2 Diabetes Loci Identified in Genome-Wide Association Studies with Metabolic Syndrome and Its Components in a Chinese Population with Type 2 Diabetes

Purpose: Several novel genetic variants for type 2 diabetes mellitus (T2DM) have been identified through genome-wide association studies (GWAS). A case-controll study was performed to investigate the association of five new European or South Asian GWAS-derived susceptibility loci with T2DM in a Chinese population. Methods: Five single nucleotide polymorphisms (SNPs) were genotyped: rs3923113 near GRB14, rs16861329 in ST6GAL1, rs1802295 in VPS26A, rs7178572 in HMG20A, and rs231362 near KCNQ1, by high-resolution melting (HRM) of small amplicons. The association between T2DM and related quantitative traits in a total of 900 Chinese individuals, including 498 type 2 diabetic patients and 402 ethnically matched control subjects, were examined. Results: After adjusting for age and gender, rs1802295 (OR 5.724, P=0.03) and rs231362 (OR=5.683, P=0.016) were found to be associated with T2DM. Triglyceride levels were higher in TT and CT carriers for rs16861329 (1.05 (0.8-1.34) mmol/l) than in CC carriers (0.91 (0.73-1.23) mmol/l) with P=0.008 and that high-density lipoprotein cholesterol (HDL-C) was lower in TT and CT carriers (1.17 (1.02-1.33) mmol/l) than in CC carriers (1.21 (1.05-1.41) mmol/l), with P=0.034. For rs3923113, the HDL-C levels were lower in the GG carriers (1.08 (0.90-1.18) mmol/l) than in the GT+TT carriers (1.21 (1.04-1.38) mmol/l), with P=0.018. Ours is the first report of this association. Conclusion: rs231362-KCNQ1 and rs1802295-VPS26A are associated with T2DM in the Chinese population. The remaining three SNPs are associated with other aspects of lipid metabolism.

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Genome-Wide Association Studies Identify Two Novel Loci Conferring Susceptibility to Diabetic Retinopathy in Japanese Patients with Type 2 Diabetes

Human Molecular Genetics ◽

10.1093/hmg/ddab044 ◽

2021 ◽

Author(s):

Minako Imamura ◽

Atsushi Takahashi ◽

Masatoshi Matsunami ◽

Momoko Horikoshi ◽

Minoru Iwata ◽

...

Keyword(s):

Type 2 Diabetes ◽

Diabetic Retinopathy ◽

Association Studies ◽

Meta Analysis ◽

Japanese Patients ◽

Genome Wide Association ◽

Genome Wide Association Studies ◽

Genome Wide ◽

Stage 1

Abstract Several reports have suggested that genetic susceptibility contributes to the development and progression of diabetic retinopathy. We aimed to identify genetic loci that confer susceptibility to diabetic retinopathy in Japanese patients with type 2 diabetes. We analysed 5 790 508 single nucleotide polymorphisms (SNPs) in 8880 Japanese patients with type 2 diabetes, 4839 retinopathy cases and 4041 controls, as well as 2217 independent Japanese patients with type 2 diabetes, 693 retinopathy cases, and 1524 controls. The results of these two genome-wide association studies (GWAS) were combined with an inverse variance meta-analysis (Stage-1), followed by de novo genotyping for the candidate SNP loci (p < 1.0 × 10−4) in an independent case–control study (Stage-2, 2260 cases and 723 controls). After combining the association data (Stage-1 and -2) using meta-analysis, the associations of two loci reached a genome-wide significance level: rs12630354 near STT3B on chromosome 3, p = 1.62 × 10−9, odds ratio (OR) = 1.17, 95% confidence interval (CI) 1.11–1.23, and rs140508424 within PALM2 on chromosome 9, p = 4.19 × 10−8, OR = 1.61, 95% CI 1.36–1.91. However, the association of these two loci were not replicated in Korean, European, or African American populations. Gene-based analysis using Stage-1 GWAS data identified a gene-level association of EHD3 with susceptibility to diabetic retinopathy (p = 2.17 × 10−6). In conclusion, we identified two novel SNP loci, STT3B and PALM2, and a novel gene, EHD3, that confers susceptibility to diabetic retinopathy; however, further replication studies are required to validate these associations.

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