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Ruiz-Narváez EA, Cozier Y, Zirpoli G, Rosenberg L, Palmer JR. Perceived Experiences of racism in Relation to Genome-Wide DNA Methylation and Epigenetic Aging in the Black Women's Health Study. J Racial Ethn Health Disparities 2024:10.1007/s40615-024-01915-3. [PMID: 38324238 DOI: 10.1007/s40615-024-01915-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Revised: 01/15/2024] [Accepted: 01/17/2024] [Indexed: 02/08/2024]
Abstract
BACKGROUND African American women have a disproportionate burden of disease compared to US non-Hispanic white women. Exposure to psychosocial stressors may contribute to these health disparities. Racial discrimination, a major stressor for African American women, could affect health through epigenetic mechanisms. METHODS We conducted an epigenome-wide association study (EWAS) to examine the association of interpersonal racism (in daily life and in institutional settings) with DNA methylation in blood in 384 participants of the Black Women's Health Study (BWHS). We also evaluated whether a greater number of perceived experiences of racism was associated with epigenetic aging as measured using different methylation clocks. Models were adjusted for chronological age, body mass index, years of education, neighborhood SES, geographic region of residence, alcohol drinking, smoking, and technical covariates. RESULTS Higher scores of racism in daily life were associated with higher methylation levels at the cg04494873 site in chromosome 5 (β = 0.64%; 95% CI = 0.41%, 0.87%; P = 6.35E-08). We also replicated one CpG site, cg03317714, which was inversely associated with racial discrimination in a previous EWAS among African American women. In the BWHS, higher scores of racism in daily life were associated with lower methylation levels at that CpG site (β = -0.94%; 95% CI = -1.37%, -0.51%; P = 2.2E-05). Higher racism scores were associated with accelerated epigenetic aging in more than one methylation clock. CONCLUSIONS Exposure to discriminatory events may affect the epigenome and accelerate biological aging, which may explain in part the earlier onset of disease in African American women.
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Affiliation(s)
- Edward A Ruiz-Narváez
- Department of Nutritional Sciences, School of Public Health, University of Michigan, 1415 Washington Heights, 1860 SPH I, Ann Arbor, MI, 48109, USA.
| | - Yvette Cozier
- Slone Epidemiology Center at, Boston University, Boston, MA, USA
| | - Gary Zirpoli
- Slone Epidemiology Center at, Boston University, Boston, MA, USA
| | - Lynn Rosenberg
- Slone Epidemiology Center at, Boston University, Boston, MA, USA
| | - Julie R Palmer
- Slone Epidemiology Center at, Boston University, Boston, MA, USA
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Wu Y, Palmer JR, Rosenberg L, Ruiz-Narváez EA. Admixture mapping of anthropometric traits in the Black Women's Health Study: evidence of a shared African ancestry component with birth weight and type 2 diabetes. J Hum Genet 2022; 67:331-338. [PMID: 35017682 DOI: 10.1038/s10038-022-01010-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 12/27/2021] [Accepted: 12/29/2021] [Indexed: 11/09/2022]
Abstract
Prevalence of obesity, type 2 diabetes (T2D), and being born with low birth weight are much higher in African American women compared to U.S. white women. Genetic factors may contribute to the excess risk of these conditions. We conducted admixture mapping of body mass index (BMI) at age 18, adult BMI, and adult waist circumference and waist-to-hip ratio adjusted for BMI using 2918 ancestral informative markers in 2596 participants of the Black Women's Health Study. We also searched for evidence of shared African genetic ancestry components among the four examined anthropometric traits and among birth weight and T2D. We found that global percent African ancestry was associated with higher adult BMI. We also found that African ancestry at 9q34 was associated with lower BMI at age 18. Our shared ancestry analysis identified ten genomic regions with local African ancestry associated with multiple traits. Seven out of these ten genomic loci were related to T2D risk. Of special interest is the 12q14-21 region where local African ancestry was associated with low birth weight, low BMI, high BMI-adjusted waist-to-hip ratio, and high T2D risk. Findings in the 12q14-21 genomic locus are consistent with the fetal insulin hypothesis that postulates that low birth weight and T2D have a common genetic basis, and they support the hypothesis of a shared African genetic ancestry component linking low birth weight and T2D in African Americans. Future studies should identify the actual genetic variants responsible for the clustering of these conditions in African Americans.
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Affiliation(s)
- Yue Wu
- Department of Bioinformatics and Biostatistics, School of Life Science and Technology, Shanghai Jiao Tong University, Shanghai, China.,Department of Nutritional Sciences, University of Michigan School of Public Health, Ann Arbor, MI, USA
| | - Julie R Palmer
- Slone Epidemiology Center at Boston University, Boston, MA, USA
| | - Lynn Rosenberg
- Slone Epidemiology Center at Boston University, Boston, MA, USA
| | - Edward A Ruiz-Narváez
- Department of Nutritional Sciences, University of Michigan School of Public Health, Ann Arbor, MI, USA.
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Farmaki AE, Garfield V, Eastwood SV, Farmer RE, Mathur R, Giannakopoulou O, Patalay P, Kuchenbaecker K, Sattar N, Hughes A, Bhaskaran K, Smeeth L, Chaturvedi N. Type 2 diabetes risks and determinants in second-generation migrants and mixed ethnicity people of South Asian and African Caribbean descent in the UK. Diabetologia 2022; 65:113-127. [PMID: 34668055 PMCID: PMC8660755 DOI: 10.1007/s00125-021-05580-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Accepted: 03/26/2021] [Indexed: 11/24/2022]
Abstract
AIMS/HYPOTHESIS Excess risks of type 2 diabetes in UK South Asians (SA) and African Caribbeans (AC) compared with Europeans remain unexplained. We studied risks and determinants of type 2 diabetes in first- and second-generation (born in the UK) migrants, and in those of mixed ethnicity. METHODS Data from the UK Biobank, a population-based cohort of ~500,000 participants aged 40-69 at recruitment, were used. Type 2 diabetes was assigned using self-report and HbA1c. Ethnicity was both self-reported and genetically assigned using admixture level scores. European, mixed European/South Asian (MixESA), mixed European/African Caribbean (MixEAC), SA and AC groups were analysed, matched for age and sex to enable comparison. In the frames of this cross-sectional study, we compared type 2 diabetes in second- vs first-generation migrants, and mixed ethnicity vs non-mixed groups. Risks and explanations were analysed using logistic regression and mediation analysis, respectively. RESULTS Type 2 diabetes prevalence was markedly elevated in SA (599/3317 = 18%) and AC (534/4180 = 13%) compared with Europeans (140/3324 = 4%). Prevalence was lower in second- vs first-generation SA (124/1115 = 11% vs 155/1115 = 14%) and AC (163/2200 = 7% vs 227/2200 = 10%). Favourable adiposity (i.e. lower waist/hip ratio or BMI) contributed to lower risk in second-generation migrants. Type 2 diabetes in mixed populations (MixESA: 52/831 = 6%, MixEAC: 70/1045 = 7%) was lower than in comparator ethnic groups (SA: 18%, AC: 13%) and higher than in Europeans (4%). Greater socioeconomic deprivation accounted for 17% and 42% of the excess type 2 diabetes risk in MixESA and MixEAC compared with Europeans, respectively. Replacing self-reported with genetically assigned ethnicity corroborated the mixed ethnicity analysis. CONCLUSIONS/INTERPRETATION Type 2 diabetes risks in second-generation SA and AC migrants are a fifth lower than in first-generation migrants. Mixed ethnicity risks were markedly lower than SA and AC groups, though remaining higher than in Europeans. Distribution of environmental risk factors, largely obesity and socioeconomic status, appears to play a key role in accounting for ethnic differences in type 2 diabetes risk.
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Affiliation(s)
- Aliki-Eleni Farmaki
- MRC Unit for Lifelong Health and Ageing, Institute of Cardiovascular Science, University College London, London, UK.
| | - Victoria Garfield
- MRC Unit for Lifelong Health and Ageing, Institute of Cardiovascular Science, University College London, London, UK
| | - Sophie V Eastwood
- MRC Unit for Lifelong Health and Ageing, Institute of Cardiovascular Science, University College London, London, UK
| | - Ruth E Farmer
- London School of Hygiene & Tropical Medicine, London, UK
| | - Rohini Mathur
- London School of Hygiene & Tropical Medicine, London, UK
| | - Olga Giannakopoulou
- Division of Psychiatry, University College London, London, UK
- UCL Genetics Institute, University College London, London, UK
| | - Praveetha Patalay
- MRC Unit for Lifelong Health and Ageing, Institute of Cardiovascular Science, University College London, London, UK
- Centre for Longitudinal Studies, University College London, London, UK
| | - Karoline Kuchenbaecker
- Division of Psychiatry, University College London, London, UK
- UCL Genetics Institute, University College London, London, UK
| | - Naveed Sattar
- Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, UK
| | - Alun Hughes
- MRC Unit for Lifelong Health and Ageing, Institute of Cardiovascular Science, University College London, London, UK
| | | | - Liam Smeeth
- London School of Hygiene & Tropical Medicine, London, UK
| | - Nish Chaturvedi
- MRC Unit for Lifelong Health and Ageing, Institute of Cardiovascular Science, University College London, London, UK
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Ruiz-Narváez EA. Genetic architecture of type 2 diabetes and its shared genetic component with low birth weight in African Americans. Curr Opin Clin Nutr Metab Care 2021; 24:326-332. [PMID: 33883416 DOI: 10.1097/mco.0000000000000757] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE OF REVIEW Recent large-scale multiancestry efforts has contributed to our knowledge of the hereditary basis of type 2 diabetes (T2D). The present review will summarize findings of the genetic basis of T2D in African Americans, a population group with a disproportionate burden of this disease. RECENT FINDINGS To date, >400 risk genetic variants have been found to be associated with the risk of T2D across populations of different ancestries. Although these findings are based on primarily European-ancestry populations, most of the identified loci show similar associations in African Americans. Ancestry-specific analyses including genome-wide associations studies (GWAS) in African Americans, Africans; as well as admixture mapping scans in African Americans have identified additional risk variants and genomic loci associate with the risk of T2D. These efforts have also uncovered new genetic links between low birth weight and T2D. In particular, admixture mapping approaches have identified a shared genetic ancestry component of both phenotypic traits in African Americans. SUMMARY Recent findings have helped us to better understand the genetic basis of T2D in African Americans. Of particular interest are new genetic discoveries linking low birth weight and T2D, two conditions with a much higher prevalence in African Americans compared to U.S. whites. Continuing work, including large-scale sequencing efforts would add to our knowledge of the genetic architecture of T2D in African Americans, as well as genetic links with other conditions.
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Affiliation(s)
- Edward A Ruiz-Narváez
- Department of Nutritional Sciences, University of Michigan School of Public Health, Ann Arbor, Michigan, USA
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Del Bosque-Plata L, Martínez-Martínez E, Espinoza-Camacho MÁ, Gragnoli C. The Role of TCF7L2 in Type 2 Diabetes. Diabetes 2021; 70:1220-1228. [PMID: 34016596 PMCID: PMC8275893 DOI: 10.2337/db20-0573] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 03/19/2021] [Indexed: 12/16/2022]
Abstract
TCF7L2 is the most potent locus for type 2 diabetes (T2D) risk and the first locus to have been robustly reported by genomic linkage studies. TCF7L2 is a transcription factor that forms a basic part of the Wnt signaling pathway. This gene has highly conserved sequence regions that correspond to functional domains. The association of TCF7L2 with T2D is one of the most powerful genetically discovered in studies of complex diseases, as it has been consistently replicated in multiple populations with diverse genetic origins. The mechanisms over which TCF7L2 exerts its effect on T2D are still not well understood. In this article, we describe the main molecular mechanisms of how TCF7L2 is related to T2D. TCF7L2 variants associated with T2D risk exert an influence on the initial therapeutic success of the hypoglycemic oral agent sulfonylurea. Thus, it is important to know whether there are other TCF7L2 variants associated with T2D that can influence treatment with oral hypoglycemic agents. Resequencing of the TCF7L2 gene in diverse ethnic groups is required to reveal common and rare variations and their role in different pathologies and in adverse reactions to drugs. Identification of TCF7L2-susceptibility disease variants will permit, at a given moment, offering of therapies to patients according to their genotype.
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Affiliation(s)
- Laura Del Bosque-Plata
- Laboratory of Nutrigenetics and Nutrigenomics, National Institute of Genomic Medicine, Mexico City, Mexico
| | - Eduardo Martínez-Martínez
- Laboratory of Cell Communication and Extracellular Vesicles, National Institute of Genomic Medicine, Mexico City, Mexico
| | | | - Claudia Gragnoli
- Division of Endocrinology, Department of Medicine, School of Medicine, Creighton University, Omaha, NE
- Division of Endocrinology, Diabetes, and Metabolic Disease, Department of Medicine, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA
- Department of Public Health Sciences, Penn State College of Medicine, Hershey, PA
- Molecular Biology Laboratory, Bios Biotech Multi-Diagnostic Health Center, Rome, Italy
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Lee EY, Mak ACY, Hu D, Sajuthi S, White MJ, Keys KL, Eckalbar W, Bonser L, Huntsman S, Urbanek C, Eng C, Jain D, Abecasis G, Kang HM, Germer S, Zody MC, Nickerson DA, Erle D, Ziv E, Rodriguez-Santana J, Seibold MA, Burchard EG. Whole-Genome Sequencing Identifies Novel Functional Loci Associated with Lung Function in Puerto Rican Youth. Am J Respir Crit Care Med 2020; 202:962-972. [PMID: 32459537 PMCID: PMC7528787 DOI: 10.1164/rccm.202002-0351oc] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Accepted: 05/27/2020] [Indexed: 12/22/2022] Open
Abstract
Rationale: Puerto Ricans have the highest childhood asthma prevalence in the United States (23.6%); however, the etiology is uncertain.Objectives: In this study, we sought to uncover the genetic architecture of lung function in Puerto Rican youth with and without asthma who were recruited from the island (n = 836).Methods: We used admixture-mapping and whole-genome sequencing data to discover genomic regions associated with lung function. Functional roles of the prioritized candidate SNPs were examined with chromatin immunoprecipitation sequencing, RNA sequencing, and expression quantitative trait loci data.Measurements and Main Results: We discovered a genomic region at 1q32 that was significantly associated with a 0.12-L decrease in the lung volume of exhaled air (95% confidence interval, -0.17 to -0.07; P = 6.62 × 10-8) with each allele of African ancestry. Within this region, two SNPs were expression quantitative trait loci of TMEM9 in nasal airway epithelial cells and MROH3P in esophagus mucosa. The minor alleles of these SNPs were associated with significantly decreased lung function and decreased TMEM9 gene expression. Another admixture-mapping peak was observed on chromosome 5q35.1, indicating that each Native American ancestry allele was associated with a 0.15-L increase in lung function (95% confidence interval, 0.08-0.21; P = 5.03 × 10-6). The region-based association tests identified four suggestive windows that harbored candidate rare variants associated with lung function.Conclusions: We identified common and rare genetic variants that may play a critical role in lung function among Puerto Rican youth. We independently validated an inflammatory pathway that could potentially be used to develop more targeted treatments and interventions for patients with asthma.
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Affiliation(s)
- Eunice Y. Lee
- Department of Bioengineering and Therapeutic Sciences and
- Department of Medicine, University of California, San Francisco, San Francisco, California
| | - Angel C. Y. Mak
- Department of Medicine, University of California, San Francisco, San Francisco, California
| | - Donglei Hu
- Department of Medicine, University of California, San Francisco, San Francisco, California
| | - Satria Sajuthi
- Department of Pediatrics, Center for Genes, Environment, and Health, and
| | - Marquitta J. White
- Department of Medicine, University of California, San Francisco, San Francisco, California
| | - Kevin L. Keys
- Department of Medicine, University of California, San Francisco, San Francisco, California
| | | | - Luke Bonser
- Department of Medicine, University of California, San Francisco, San Francisco, California
| | - Scott Huntsman
- Department of Medicine, University of California, San Francisco, San Francisco, California
| | - Cydney Urbanek
- Department of Pediatrics, Center for Genes, Environment, and Health, and
| | - Celeste Eng
- Department of Medicine, University of California, San Francisco, San Francisco, California
| | | | - Gonçalo Abecasis
- Center for Statistical Genetics, University of Michigan, Ann Arbor, Michigan
- Regeneron Pharmaceuticals, Tarrytown, New York
| | - Hyun M. Kang
- Center for Statistical Genetics, University of Michigan, Ann Arbor, Michigan
| | | | | | - Deborah A. Nickerson
- Department of Genome Sciences, University of Washington, Seattle, Washington
- Northwest Genomics Center, Seattle, Washington
- Brotman Baty Institute, Seattle, Washington
| | - David Erle
- Department of Medicine, University of California, San Francisco, San Francisco, California
| | - Elad Ziv
- Department of Medicine, University of California, San Francisco, San Francisco, California
| | | | - Max A. Seibold
- Department of Pediatrics, Center for Genes, Environment, and Health, and
- Department of Pediatrics, National Jewish Health, Denver, Colorado
- Division of Pulmonary Sciences and Critical Care Medicine, Department of Medicine, University of Colorado–Anschutz Medical Campus, Aurora, Colorado
| | - Esteban G. Burchard
- Department of Bioengineering and Therapeutic Sciences and
- Department of Medicine, University of California, San Francisco, San Francisco, California
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Franck M, de Toro-Martín J, Guénard F, Rudkowska I, Lemieux S, Lamarche B, Couture P, Vohl MC. Prevention of Potential Adverse Metabolic Effects of a Supplementation with Omega-3 Fatty Acids Using a Genetic Score Approach. Lifestyle Genom 2019; 13:32-42. [PMID: 31779001 DOI: 10.1159/000504022] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Accepted: 10/07/2019] [Indexed: 01/25/2023] Open
Abstract
INTRODUCTION The consumption of long-chain omega-3 polyunsaturated fatty acids (n-3 PUFA) has been reported to have beneficial health effects, notably, by reducing plasma triglyceride levels. Nonetheless, a concomitant decrease in insulin sensitivity has also been observed, but is highly variable among subjects. Herein, we aimed to determine the importance of the genetic background in the interindividual variability of the insulin sensitivity response following an n-3 PUFA supplementation. METHODS A total of 210 participants completed a 6-week n-3 PUFA supplementation with 5 g/day of fish oil (providing 1.9-2.2 g of eicosapentaenoic acid + 1.1 g of docosahexaenoic acid). Insulin resistance was estimated by the homeostatic model assessment (HOMA-IR), and participants were further classified as high-risk or low-risk depending on their HOMA-IR change following the n-3 PUFA supplementation, as compared to pre-supplementation values. Genome-wide genotyping data were obtained for 138 participants using HumanOmni-5-Quad BeadChips containing 4,301,331 single nucleotide polymorphisms. A genome-wide association analysis (GWAS) was carried out between high-risk and low-risk participants. The population study was split into training (60%) and testing (40%) datasets to assess the predictive accuracy of a genetic risk score (GRS) constructed by summing the number of risk alleles. RESULTS Following the n-3 PUFA supplementation, 32 participants had increased HOMA-IR as compared to initial values and were classified as high risk (23.2%), whereas remaining subjects were classified as low risk (n = 106, 76.8%). A total of 8 loci had frequency differences between high-risk and low-risk participants at a suggestive GWAS association threshold (p value <1 × 10-5). After applying 10-fold cross validation, the GRS showed a significant association with the risk of increased HOMA-IR in the testing dataset (OR = 3.16 [95% CI, 1.85-7.14]), with a predictive accuracy of 0.85, and explained 40% of variation in HOMA-IR change. CONCLUSIONS These results suggest that the genetic background has a relevant role in the interindividual variability observed in the insulin sensitivity response following an n-3 PUFA supplementation. Subjects being at risk of insulin sensitivity lowering following an n-3 PUFA supplementation may be identified using genetic-based precision nutrition approaches.
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Affiliation(s)
- Maximilien Franck
- Institute of Nutrition and Functional Foods (INAF), Laval University, Quebec City, Québec, Canada.,School of Nutrition, Laval University, Quebec City, Québec, Canada
| | - Juan de Toro-Martín
- Institute of Nutrition and Functional Foods (INAF), Laval University, Quebec City, Québec, Canada.,School of Nutrition, Laval University, Quebec City, Québec, Canada
| | - Frédéric Guénard
- Institute of Nutrition and Functional Foods (INAF), Laval University, Quebec City, Québec, Canada.,School of Nutrition, Laval University, Quebec City, Québec, Canada
| | - Iwona Rudkowska
- Department of Kinesiology, Laval University, Quebec City, Québec, Canada.,Endocrinology and Nephrology Unit, CHU de Quebec Research Center, Quebec City, Québec, Canada
| | - Simone Lemieux
- Institute of Nutrition and Functional Foods (INAF), Laval University, Quebec City, Québec, Canada.,School of Nutrition, Laval University, Quebec City, Québec, Canada
| | - Benoît Lamarche
- Institute of Nutrition and Functional Foods (INAF), Laval University, Quebec City, Québec, Canada.,School of Nutrition, Laval University, Quebec City, Québec, Canada
| | - Patrick Couture
- Institute of Nutrition and Functional Foods (INAF), Laval University, Quebec City, Québec, Canada.,Endocrinology and Nephrology Unit, CHU de Quebec Research Center, Quebec City, Québec, Canada
| | - Marie-Claude Vohl
- Institute of Nutrition and Functional Foods (INAF), Laval University, Quebec City, Québec, Canada, .,School of Nutrition, Laval University, Quebec City, Québec, Canada,
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Grinde KE, Brown LA, Reiner AP, Thornton TA, Browning SR. Genome-wide Significance Thresholds for Admixture Mapping Studies. Am J Hum Genet 2019; 104:454-465. [PMID: 30773276 PMCID: PMC6407497 DOI: 10.1016/j.ajhg.2019.01.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Accepted: 01/17/2019] [Indexed: 01/25/2023] Open
Abstract
Admixture mapping studies have become more common in recent years, due in part to technological advances and growing international efforts to increase the diversity of genetic studies. However, many open questions remain about appropriate implementation of admixture mapping studies, including how best to control for multiple testing, particularly in the presence of population structure. In this study, we develop a theoretical framework to characterize the correlation of local ancestry and admixture mapping test statistics in admixed populations with contributions from any number of ancestral populations and arbitrary population structure. Based on this framework, we develop an analytical approach for obtaining genome-wide significance thresholds for admixture mapping studies. We validate our approach via analysis of simulated traits with real genotype data for 8,064 unrelated African American and 3,425 Hispanic/Latina women from the Women's Health Initiative SNP Health Association Resource (WHI SHARe). In an application to these WHI SHARe data, our approach yields genome-wide significant p value thresholds of 2.1 × 10-5 and 4.5 × 10-6 for admixture mapping studies in the African American and Hispanic/Latina cohorts, respectively. Compared to other commonly used multiple testing correction procedures, our method is fast, easy to implement (using our publicly available R package), and controls the family-wise error rate even in structured populations. Importantly, we note that the appropriate admixture mapping significance threshold depends on the number of ancestral populations, generations since admixture, and population structure of the sample; as a result, significance thresholds are not, in general, transferable across studies.
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Affiliation(s)
- Kelsey E Grinde
- Department of Biostatistics, University of Washington, Seattle, WA 98195, USA.
| | - Lisa A Brown
- Department of Biostatistics, University of Washington, Seattle, WA 98195, USA; Seattle Genetics, Bothell, WA 98021, USA
| | - Alexander P Reiner
- Department of Epidemiology, University of Washington, Seattle, WA 98195, USA; Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Timothy A Thornton
- Department of Biostatistics, University of Washington, Seattle, WA 98195, USA
| | - Sharon R Browning
- Department of Biostatistics, University of Washington, Seattle, WA 98195, USA
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