Trans-ancestry genetic study of type 2 diabetes highlights the power of diverse populations for discovery and translation

Objective. Polygenic prediction of type 2 diabetes in continental Africans is adversely affected by the limited number of genome-wide association studies (GWAS) of type 2 diabetes from Africa and the poor transferability of European derived polygenic risk scores (PRS) in diverse ethnicities. We set out to evaluate if African American, European or multi-ethnic derived PRSs would improve polygenic prediction in continental Africans. Research Design and Methods. Using the PRSice software, ethnic-specific PRSs were computed with weights from the type 2 diabetes GWAS multi-ancestry meta-analysis of 228,499 cases and 1,178,783 controls. The South African Zulu study (1602 cases and 981 controls) was used as the target data set. Validation and assessment of the best predictive PRS association with age at diagnosis was done in the Africa America Diabetes Mellitus (AADM) study (2148 cases and 2161 controls). Results. The discriminatory ability of the African American and Multi-ethnic PRS were similar. However, the African American derived PRS was more transferable in all the countries represented in the AADM cohort, and predictive of type 2 diabetes in the country combined analysis compared to the European and multi-ethnic derived scores. Notably, participants in the 10th decile of this PRS had a 3.63-fold greater risk (OR 3.63; 95%CI (2.19 - 4.03), p = 2.79 x 10-17) per risk allele of developing diabetes and were diagnosed 2.6 years earlier compared to those in the first decile. Conclusions African American derived PRS enhances polygenic prediction of type 2 diabetes in continental Africans. Improved representation of non-European populations (including Africans) in GWAS promises to provide better tools for precision medicine interventions in type 2 diabetes.

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Polygenic prediction of type 2 diabetes in continental Africa

10.1101/2021.02.11.430719 ◽

2021 ◽

Author(s):

Tinashe Chikowore ◽

Kenneth Ekoru ◽

Marijana Vujkovic ◽

Dipender Gill ◽

Fraser Pirie ◽

...

Keyword(s):

Type 2 Diabetes ◽

African American ◽

South African ◽

Association Studies ◽

Risk Scores ◽

Genome Wide Association Studies ◽

Data Set ◽

Genome Wide ◽

Design And Methods

AbstractObjectivePolygenic prediction of type 2 diabetes in continental Africans is adversely affected by the limited number of genome-wide association studies (GWAS) of type 2 diabetes from Africa, and the poor transferability of European derived polygenic risk scores (PRS) in diverse ethnicities. We set out to evaluate if African American or multi-ethnic derived PRSs would improve polygenic prediction in continental Africans.Research Design and MethodsUsing the PRSice software, ethnic-specific PRSs were computed with weights from the type 2 diabetes GWAS of the Million Veteran Program (MVP) study. The South African Zulu study (1602 cases and 976 controls) was used as the target data set. Replication and assessment of the best predictive PRS association with age at diagnosis was done in the Africa America Diabetes Mellitus (AADM) study (1031 cases and 738 controls).ResultsThe African American derived PRS was more predictive of type 2 diabetes compared to the European and multi-ethnic derived scores. Notably, participants in the 10th decile of this PRS had a 3.19-fold greater risk (OR 3.19; 95%CI (1.94-5.29), p = 5.33 x10-6) of developing diabetes and were diagnosed 2.6 years earlier compared to those in the first decile.ConclusionsAfrican American derived PRS enhances polygenic prediction of type 2 diabetes in continental Africans. Improved representation of non-Europeans populations (including Africans) in GWAS, promises to provide better tools for precision medicine interventions in type 2 diabetes.

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Could personalised risk prediction for type 2 diabetes using polygenic risk scores direct prevention, enhance diagnostics, or improve treatment?

Wellcome Open Research ◽

10.12688/wellcomeopenres.16251.1 ◽

2020 ◽

Vol 5 ◽

pp. 206

Author(s):

Mathilde Boecker ◽

Alvina G. Lai

Keyword(s):

Type 2 Diabetes ◽

Risk Prediction ◽

Large Scale ◽

Association Studies ◽

Genome Wide Association ◽

Risk Scores ◽

Genome Wide Association Studies ◽

Polygenic Risk ◽

Genome Wide

Over the past three decades, the number of people globally with diabetes mellitus has more than doubled. It is estimated that by 2030, 439 million people will be suffering from the disease, 90-95% of whom will have type 2 diabetes (T2D). In 2017, 5 million deaths globally were attributable to T2D, placing it in the top 10 global causes of death. Because T2D is a result of both genetic and environmental factors, identification of individuals with high genetic risk can help direct early interventions to prevent progression to more serious complications. Genome-wide association studies have identified ~400 variants associated with T2D that can be used to calculate polygenic risk scores (PRS). Although PRSs are not currently more accurate than clinical predictors and do not yet predict risk with equal accuracy across all ethnic populations, they have several potential clinical uses. Here, we discuss potential usages of PRS for predicting T2D and for informing and optimising interventions. We also touch on possible health inequality risks of PRS and the feasibility of large-scale implementation of PRS in clinical practice. Before PRSs can be used as a therapeutic tool, it is important that further polygenic risk models are derived using non-European genome-wide association studies to ensure that risk prediction is accurate for all ethnic groups. Furthermore, it is essential that the ethical, social and legal implications of PRS are considered before their implementation in any context.

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Polygenic Prediction of Type 2 Diabetes in Africa

10.2337/figshare.17076419 ◽

2022 ◽

Author(s):

Tinashe Chikowore ◽

Kenneth Ekoru ◽

Marijana Vujkovic ◽

Dipender Gill ◽

Fraser Pirie ◽

...

Keyword(s):

Type 2 Diabetes ◽

African American ◽

Association Studies ◽

Meta Analysis ◽

Risk Scores ◽

Genome Wide Association Studies ◽

Data Set ◽

Genome Wide ◽

Design And Methods

Objective. Polygenic prediction of type 2 diabetes in continental Africans is adversely affected by the limited number of genome-wide association studies (GWAS) of type 2 diabetes from Africa and the poor transferability of European derived polygenic risk scores (PRS) in diverse ethnicities. We set out to evaluate if African American, European or multi-ethnic derived PRSs would improve polygenic prediction in continental Africans. Research Design and Methods. Using the PRSice software, ethnic-specific PRSs were computed with weights from the type 2 diabetes GWAS multi-ancestry meta-analysis of 228,499 cases and 1,178,783 controls. The South African Zulu study (1602 cases and 981 controls) was used as the target data set. Validation and assessment of the best predictive PRS association with age at diagnosis was done in the Africa America Diabetes Mellitus (AADM) study (2148 cases and 2161 controls). Results. The discriminatory ability of the African American and Multi-ethnic PRS were similar. However, the African American derived PRS was more transferable in all the countries represented in the AADM cohort, and predictive of type 2 diabetes in the country combined analysis compared to the European and multi-ethnic derived scores. Notably, participants in the 10th decile of this PRS had a 3.63-fold greater risk (OR 3.63; 95%CI (2.19 - 4.03), p = 2.79 x 10-17) per risk allele of developing diabetes and were diagnosed 2.6 years earlier compared to those in the first decile. Conclusions African American derived PRS enhances polygenic prediction of type 2 diabetes in continental Africans. Improved representation of non-European populations (including Africans) in GWAS promises to provide better tools for precision medicine interventions in type 2 diabetes.

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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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