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1.
Cell ; 184(8): 2068-2083.e11, 2021 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-33861964

RESUMO

Understanding population health disparities is an essential component of equitable precision health efforts. Epidemiology research often relies on definitions of race and ethnicity, but these population labels may not adequately capture disease burdens and environmental factors impacting specific sub-populations. Here, we propose a framework for repurposing data from electronic health records (EHRs) in concert with genomic data to explore the demographic ties that can impact disease burdens. Using data from a diverse biobank in New York City, we identified 17 communities sharing recent genetic ancestry. We observed 1,177 health outcomes that were statistically associated with a specific group and demonstrated significant differences in the segregation of genetic variants contributing to Mendelian diseases. We also demonstrated that fine-scale population structure can impact the prediction of complex disease risk within groups. This work reinforces the utility of linking genomic data to EHRs and provides a framework toward fine-scale monitoring of population health.

2.
Clin Transl Sci ; 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33650294

RESUMO

To compare etonogestrel pharmacokinetic and pharmacodynamic outcomes by both self-reported race/ethnicity and genetically-determined ancestry among contraceptive implant users. We conducted a secondary analysis of our parent pharmacogenomic study of 350 implant users. We genotyped these reproductive-aged (18-45 years) women for 88 ancestry-informative single nucleotide polymorphisms. We then assigned each participant a proportion value for African (AFR), European (EUR), and Indigenous American (AMR) ancestry based on reference population data. We correlated genetic ancestry with self-reported race/ethnicity and utilized genetic ancestry proportion values as variables for previously-performed association analyses with serum etonogestrel concentrations and progestin-related side effects (e.g. bothersome bleeding, subjective weight gain). We successfully estimated genetically-determined ancestry for 332 participants. EUR, AFR, and AMR ancestry were each highly correlated with self-reported White/Non-Hispanic race (r=0.64, p=4.14x10-40 ), Black/African American race (r=0.88, p=1.36x10-107 ), and Hispanic/Latina ethnicity (r=0.68, p=4.03x10-47 ), respectively. Neither genetically-determined ancestry nor self-reported race/ethnicity were significantly associated with serum etonogestrel concentrations. AFR ancestry and self-reported Black race had similar associations with reporting monthly periods (OR 2.18, p=0.09 vs OR 2.22, p=0.02) and having received treatment for bothersome bleeding (OR 5.19, p=0.005 vs OR 4.73, p=2.0x10-4 ). In multivariable logistic regression for subjective weight gain, AMR ancestry dropped out of the model in preference for self-reported Hispanic/Latina ethnicity. We found no new associations between genetically-determined ancestry and contraceptive implant pharmacodynamics/pharmacokinetics. Self-reported race/ethnicity were strong surrogates for genetically-determined ancestry among this population of contraceptive implant users. Our data suggest that self-reported race/ethnicity, capturing societal and cultural aspects, remain important to the investigation of progestin-related side effects.

3.
Mol Biol Evol ; 2021 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-33616658

RESUMO

Human natural killer (NK) cells are essential for controlling infection, cancer and fetal development. NK cell functions are modulated by interactions between polymorphic inhibitory killer cell immunoglobulin-like receptors (KIR) and polymorphic HLA-A, -B and -C ligands expressed on tissue cells. All HLA-C alleles encode a KIR ligand and contribute to reproduction and immunity. In contrast, only some HLA-A and -B alleles encode KIR ligands and they focus on immunity. By high-resolution analysis of KIR and HLA-A, -B and -C genes, we show that the Chinese Southern Han are significantly enriched for interactions between inhibitory KIR and HLA-A and -B. This enrichment has had substantial input through population admixture with neighboring populations, who contributed HLA class I haplotypes expressing the KIR ligands B*46:01 and B*58:01, which subsequently rose to high frequency by natural selection. Consequently, over 80% of Southern Han HLA haplotypes encode more than one KIR ligand. Complementing the high number of KIR ligands, the Chinese Southern Han KIR locus combines a high frequency of genes expressing potent inhibitory KIR, with a low frequency of those expressing activating KIR. The Southern Han centromeric KIR region encodes strong, conserved, inhibitory HLA-C specific receptors, and the telomeric region provides a high number and diversity of inhibitory HLA-A and -B specific receptors. In all these characteristics, the Chinese Southern Han represent other East Asians, whose NK cell repertoires are thus enhanced in quantity, diversity and effector strength, likely augmenting resistance to endemic viral infections.

5.
PLoS Genet ; 16(8): e1008927, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32797036

RESUMO

The genetic control of gene expression is a core component of human physiology. For the past several years, transcriptome-wide association studies have leveraged large datasets of linked genotype and RNA sequencing information to create a powerful gene-based test of association that has been used in dozens of studies. While numerous discoveries have been made, the populations in the training data are overwhelmingly of European descent, and little is known about the generalizability of these models to other populations. Here, we test for cross-population generalizability of gene expression prediction models using a dataset of African American individuals with RNA-Seq data in whole blood. We find that the default models trained in large datasets such as GTEx and DGN fare poorly in African Americans, with a notable reduction in prediction accuracy when compared to European Americans. We replicate these limitations in cross-population generalizability using the five populations in the GEUVADIS dataset. Via realistic simulations of both populations and gene expression, we show that accurate cross-population generalizability of transcriptome prediction only arises when eQTL architecture is substantially shared across populations. In contrast, models with non-identical eQTLs showed patterns similar to real-world data. Therefore, generating RNA-Seq data in diverse populations is a critical step towards multi-ethnic utility of gene expression prediction.


Assuntos
Afro-Americanos/genética , Estudo de Associação Genômica Ampla/métodos , Modelos Genéticos , Transcriptoma , Perfilação da Expressão Gênica/métodos , Perfilação da Expressão Gênica/normas , Estudo de Associação Genômica Ampla/normas , Humanos , Locos de Características Quantitativas , RNA-Seq/métodos , RNA-Seq/normas , Padrões de Referência
6.
Nature ; 583(7817): 572-577, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32641827

RESUMO

The possibility of voyaging contact between prehistoric Polynesian and Native American populations has long intrigued researchers. Proponents have pointed to the existence of New World crops, such as the sweet potato and bottle gourd, in the Polynesian archaeological record, but nowhere else outside the pre-Columbian Americas1-6, while critics have argued that these botanical dispersals need not have been human mediated7. The Norwegian explorer Thor Heyerdahl controversially suggested that prehistoric South American populations had an important role in the settlement of east Polynesia and particularly of Easter Island (Rapa Nui)2. Several limited molecular genetic studies have reached opposing conclusions, and the possibility continues to be as hotly contested today as it was when first suggested8-12. Here we analyse genome-wide variation in individuals from islands across Polynesia for signs of Native American admixture, analysing 807 individuals from 17 island populations and 15 Pacific coast Native American groups. We find conclusive evidence for prehistoric contact of Polynesian individuals with Native American individuals (around AD 1200) contemporaneous with the settlement of remote Oceania13-15. Our analyses suggest strongly that a single contact event occurred in eastern Polynesia, before the settlement of Rapa Nui, between Polynesian individuals and a Native American group most closely related to the indigenous inhabitants of present-day Colombia.


Assuntos
Fluxo Gênico/genética , Genoma Humano/genética , Migração Humana/história , Índios Centro-Americanos/genética , Índios Sul-Americanos/genética , Ilhas , Grupo com Ancestrais Oceânicos/genética , América Central/etnologia , Colômbia/etnologia , Europa (Continente)/etnologia , Genética Populacional , História Medieval , Humanos , Polimorfismo de Nucleotídeo Único/genética , Polinésia , América do Sul/etnologia , Fatores de Tempo
7.
Biol Res ; 53(1): 15, 2020 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-32299502

RESUMO

BACKGROUND: Current South American populations trace their origins mainly to three continental ancestries, i.e. European, Amerindian and African. Individual variation in relative proportions of each of these ancestries may be confounded with socio-economic factors due to population stratification. Therefore, ancestry is a potential confounder variable that should be considered in epidemiologic studies and in public health plans. However, there are few studies that have assessed the ancestry of the current admixed Chilean population. This is partly due to the high cost of genome-scale technologies commonly used to estimate ancestry. In this study we have designed a small panel of SNPs to accurately assess ancestry in the largest sampling to date of the Chilean mestizo population (n = 3349) from eight cities. Our panel is also able to distinguish between the two main Amerindian components of Chileans: Aymara from the north and Mapuche from the south. RESULTS: A panel of 150 ancestry-informative markers (AIMs) of SNP type was selected to maximize ancestry informativeness and genome coverage. Of these, 147 were successfully genotyped by KASPar assays in 2843 samples, with an average missing rate of 0.012, and a 0.95 concordance with microarray data. The ancestries estimated with the panel of AIMs had relative high correlations (0.88 for European, 0.91 for Amerindian, 0.70 for Aymara, and 0.68 for Mapuche components) with those obtained with AXIOM LAT1 array. The country's average ancestry was 0.53 ± 0.14 European, 0.04 ± 0.04 African, and 0.42 ± 0.14 Amerindian, disaggregated into 0.18 ± 0.15 Aymara and 0.25 ± 0.13 Mapuche. However, Mapuche ancestry was highest in the south (40.03%) and Aymara in the north (35.61%) as expected from the historical location of these ethnic groups. We make our results available through an online app and demonstrate how it can be used to adjust for ancestry when testing association between incidence of a disease and nongenetic risk factors. CONCLUSIONS: We have conducted the most extensive sampling, across many different cities, of current Chilean population. Ancestry varied significantly by latitude and human development. The panel of AIMs is available to the community for estimating ancestry at low cost in Chileans and other populations with similar ancestry.


Assuntos
Grupos Étnicos/genética , Genética Populacional/organização & administração , Índios Sul-Americanos/genética , Polimorfismo de Nucleotídeo Único/genética , Grupos Populacionais/genética , Chile , Feminino , Frequência do Gene/genética , Marcadores Genéticos/genética , Genótipo , Técnicas de Genotipagem , Humanos , Masculino , Filogeografia , Saliva
8.
J Hepatol ; 72(6): 1070-1081, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32145261

RESUMO

BACKGROUND & AIMS: The Ile138Met variant (rs738409) in the PNPLA3 gene has the largest effect on non-alcoholic fatty liver disease (NAFLD), increasing the risk of progression to severe forms of liver disease. It remains unknown if the variant plays a role in age of NAFLD onset. We aimed to determine if rs738409 impacts on the age of NAFLD diagnosis. METHODS: We applied a novel natural language processing (NLP) algorithm to a longitudinal electronic health records (EHR) dataset of >27,000 individuals with genetic data from a multi-ethnic biobank, defining NAFLD cases (n = 1,703) and confirming controls (n = 8,119). We conducted i) a survival analysis to determine if age at diagnosis differed by rs738409 genotype, ii) a receiver operating characteristics analysis to assess the utility of the rs738409 genotype in discriminating NAFLD cases from controls, and iii) a phenome-wide association study (PheWAS) between rs738409 and 10,095 EHR-derived disease diagnoses. RESULTS: The PNPLA3 G risk allele was associated with: i) earlier age of NAFLD diagnosis, with the strongest effect in Hispanics (hazard ratio 1.33; 95% CI 1.15-1.53; p <0.0001) among whom a NAFLD diagnosis was 15% more likely in risk allele carriers vs. non-carriers; ii) increased NAFLD risk (odds ratio 1.61; 95% CI 1.349-1.73; p <0.0001), with the strongest effect among Hispanics (odds ratio 1.43; 95% CI 1.28-1.59; p <0.0001); iii) additional liver diseases in a PheWAS (p <4.95 × 10-6) where the risk variant also associated with earlier age of diagnosis. CONCLUSION: Given the role of the rs738409 in NAFLD diagnosis age, our results suggest that stratifying risk within populations known to have an enhanced risk of liver disease, such as Hispanic carriers of the rs738409 variant, would be effective in earlier identification of those who would benefit most from early NAFLD prevention and treatment strategies. LAY SUMMARY: Despite clear associations between the PNPLA3 rs738409 variant and elevated risk of progression from non-alcoholic fatty liver disease (NAFLD) to more severe forms of liver disease, it remains unknown if PNPLA3 rs738409 plays a role in the age of NAFLD onset. Herein, we found that this risk variant is associated with an earlier age of NAFLD and other liver disease diagnoses; an observation most pronounced in Hispanic Americans. We conclude that PNPLA3 rs738409 could be used to better understand liver disease risk within vulnerable populations and identify patients that may benefit from early prevention strategies.

9.
Mol Biol Evol ; 37(4): 994-1006, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-31848607

RESUMO

Native American genetic variation remains underrepresented in most catalogs of human genome sequencing data. Previous genotyping efforts have revealed that Mexico's Indigenous population is highly differentiated and substructured, thus potentially harboring higher proportions of private genetic variants of functional and biomedical relevance. Here we have targeted the coding fraction of the genome and characterized its full site frequency spectrum by sequencing 76 exomes from five Indigenous populations across Mexico. Using diffusion approximations, we modeled the demographic history of Indigenous populations from Mexico with northern and southern ethnic groups splitting 7.2 KYA and subsequently diverging locally 6.5 and 5.7 KYA, respectively. Selection scans for positive selection revealed BCL2L13 and KBTBD8 genes as potential candidates for adaptive evolution in Rarámuris and Triquis, respectively. BCL2L13 is highly expressed in skeletal muscle and could be related to physical endurance, a well-known phenotype of the northern Mexico Rarámuri. The KBTBD8 gene has been associated with idiopathic short stature and we found it to be highly differentiated in Triqui, a southern Indigenous group from Oaxaca whose height is extremely low compared to other Native populations.

10.
Biol. Res ; 53: 15, 2020. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1100921

RESUMO

BACKGROUND: Current South American populations trace their origins mainly to three continental ancestries, i.e. European, Amerindian and African. Individual variation in relative proportions of each of these ancestries may be confounded with socio-economic factors due to population stratification. Therefore, ancestry is a potential confounder variable that should be considered in epidemiologic studies and in public health plans. However, there are few studies that have assessed the ancestry of the current admixed Chilean population. This is partly due to the high cost of genome-scale technologies commonly used to estimate ancestry. In this study we have designed a small panel of SNPs to accurately assess ancestry in the largest sampling to date of the Chilean mestizo population (n = 3349) from eight cities. Our panel is also able to distinguish between the two main Amerindian components of Chileans: Aymara from the north and Mapuche from the south. RESULTS: A panel of 150 ancestry-informative markers (AIMs) of SNP type was selected to maximize ancestry informativeness and genome coverage. Of these, 147 were successfully genotyped by KASPar assays in 2843 samples, with an average missing rate of 0.012, and a 0.95 concordance with microarray data. The ancestries estimated with the panel of AIMs had relative high correlations (0.88 for European, 0.91 for Amerindian, 0.70 for Aymara, and 0.68 for Mapuche components) with those obtained with AXIOM LAT1 array. The country's average ancestry was 0.53 ± 0.14 European, 0.04 ± 0.04 African, and 0.42 ± 0.14 Amerindian, disaggregated into 0.18 ± 0.15 Aymara and 0.25 ± 0.13 Mapuche. However, Mapuche ancestry was highest in the south (40.03%) and Aymara in the north (35.61%) as expected from the historical location of these ethnic groups. We make our results available through an online app and demonstrate how it can be used to adjust for ancestry when testing association between incidence of a disease and nongenetic risk factors. CONCLUSIONS: We have conducted the most extensive sampling, across many different cities, of current Chilean population. Ancestry varied significantly by latitude and human development. The panel of AIMs is available to the community for estimating ancestry at low cost in Chileans and other populations with similar ancestry.


Assuntos
Humanos , Masculino , Feminino , Grupos Étnicos/genética , Índios Sul-Americanos/genética , Polimorfismo de Nucleotídeo Único/genética , Grupos Populacionais/genética , Genética Populacional/organização & administração , Saliva , Marcadores Genéticos/genética , Chile , Filogeografia , Técnicas de Genotipagem , Frequência do Gene/genética , Genótipo
12.
Nature ; 570(7762): 514-518, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31217584

RESUMO

Genome-wide association studies (GWAS) have laid the foundation for investigations into the biology of complex traits, drug development and clinical guidelines. However, the majority of discovery efforts are based on data from populations of European ancestry1-3. In light of the differential genetic architecture that is known to exist between populations, bias in representation can exacerbate existing disease and healthcare disparities. Critical variants may be missed if they have a low frequency or are completely absent in European populations, especially as the field shifts its attention towards rare variants, which are more likely to be population-specific4-10. Additionally, effect sizes and their derived risk prediction scores derived in one population may not accurately extrapolate to other populations11,12. Here we demonstrate the value of diverse, multi-ethnic participants in large-scale genomic studies. The Population Architecture using Genomics and Epidemiology (PAGE) study conducted a GWAS of 26 clinical and behavioural phenotypes in 49,839 non-European individuals. Using strategies tailored for analysis of multi-ethnic and admixed populations, we describe a framework for analysing diverse populations, identify 27 novel loci and 38 secondary signals at known loci, as well as replicate 1,444 GWAS catalogue associations across these traits. Our data show evidence of effect-size heterogeneity across ancestries for published GWAS associations, substantial benefits for fine-mapping using diverse cohorts and insights into clinical implications. In the United States-where minority populations have a disproportionately higher burden of chronic conditions13-the lack of representation of diverse populations in genetic research will result in inequitable access to precision medicine for those with the highest burden of disease. We strongly advocate for continued, large genome-wide efforts in diverse populations to maximize genetic discovery and reduce health disparities.


Assuntos
Grupo com Ancestrais do Continente Africano/genética , Grupo com Ancestrais do Continente Asiático/genética , Estudo de Associação Genômica Ampla/métodos , Hispano-Americanos/genética , Grupos Minoritários , Herança Multifatorial/genética , Saúde da Mulher , Estatura/genética , Estudos de Coortes , Feminino , Genética Médica/métodos , Equidade em Saúde/tendências , Disparidades nos Níveis de Saúde , Humanos , Masculino , Estados Unidos
13.
Am J Clin Nutr ; 110(1): 16-23, 2019 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-31161206

RESUMO

BACKGROUND: African Americans (AAs) and Hispanic/Latinos (HLs) have higher risk of obesity than European Americans, possibly due to differences in environment and lifestyle, but also reflecting differences in genetic background. OBJECTIVE: To gain insight into factors contributing to BMI (in kg/m2) and obesity risk (BMI ≥ 30) among ancestry groups, we investigate the role of self-reported ancestry, proportion of genetic African ancestry, and country of birth in 6368 self-identified AA and 7569 HL participants of the New York-based BioMe Biobank. METHODS: AAs and HLs are admixed populations that trace their genetic ancestry to the Americas, Africa, and Europe. The proportion of African ancestry (PAA), quantified using ADMIXTURE, was higher among self-reported AA (median: 87%; IQR: 79-92%) than among HL (26%; 15-41%) participants. Approximately 18% of AA and 59% of HL participants were non-US-born. RESULTS: Because of significant differences between sexes (PPAA*sex interaction = 4.8 × 10-22), we considered women and men separately. Among women, country of birth and genetic ancestry contributed independently to BMI. US-born women had a BMI 1.99 higher than those born abroad (P = 7.7 × 10-25). Every 10% increase in PAA was associated with a BMI 0.29 higher (P = 7.1 × 10-10). After accounting for PAA and country of birth, the contribution of self-reported ancestry was small (P = 0.046). The contribution of PAA to higher BMI was significantly more pronounced among US-born (0.35/10%PAA, P = 0.003) than among non-US-born (0.26/10%PAA, P = 0.01) women (PPAA*sex interaction = 0.004). In contrast, among men, only US-born status influenced BMI. US-born men had a BMI 1.33 higher than non-US-born men, whereas PAA and self-reported ancestry were not associated with BMI. Associations with obesity risk were similar to those observed for BMI. CONCLUSIONS: Being US-born is associated with a substantially higher BMI and risk of obesity in both men and women. Genetic ancestry, but not self-reported ancestry, is associated with obesity susceptibility, but only among US-born women in this New York-based population.


Assuntos
Afro-Americanos/genética , Grupos de Populações Continentais/genética , Predisposição Genética para Doença , Hispano-Americanos/genética , Obesidade/genética , Grupo com Ancestrais do Continente Africano/genética , Fatores Etários , Idoso , Índice de Massa Corporal , Grupo com Ancestrais do Continente Europeu/genética , Feminino , Técnicas de Genotipagem , Humanos , Estilo de Vida , Masculino , Pessoa de Meia-Idade , Características de Residência , Fatores Sexuais , Estados Unidos/etnologia
14.
Annu Rev Genomics Hum Genet ; 20: 181-200, 2019 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-30978304

RESUMO

The past decade has seen a technological revolution in human genetics that has empowered population-level investigations into genetic associations with phenotypes. Although these discoveries rely on genetic variation across individuals, association studies have overwhelmingly been performed in populations of European descent. In this review, we describe limitations faced by single-population studies and provide an overview of strategies to improve global representation in existing data sets and future human genomics research via diversity-focused, multiethnic studies. We highlight the successes of individual studies and meta-analysis consortia that have provided unique knowledge. Additionally, we outline the approach taken by the Population Architecture Using Genomics and Epidemiology (PAGE) study to develop best practices for performing genetic epidemiology in multiethnic contexts. Finally, we discuss how limiting investigations to single populations impairs findings in the clinical domain for both rare-variant identification and genetic risk prediction.


Assuntos
Grupos de Populações Continentais/genética , Grupos Étnicos/genética , Variação Genética , Genética Humana/tendências , Metagenômica/tendências , Epidemiologia Molecular/tendências , Viés , Bases de Dados Factuais , Genoma Humano , Estudo de Associação Genômica Ampla , Genótipo , Humanos , Fenótipo
15.
Front Immunol ; 10: 24, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30745901

RESUMO

Natural killer (NK) cell functions are modulated by polymorphic killer cell immunoglobulin-like receptors (KIR). Among 13 human KIR genes, which vary by presence and copy number, KIR3DL3 is ubiquitously present in every individual across diverse populations. No ligand or function is known for KIR3DL3, but limited knowledge of expression suggests involvement in reproduction, likely during placentation. With 157 human alleles, KIR3DL3 is also highly polymorphic and we show heterozygosity exceeds that of HLA-B in many populations. The external domains of catarrhine primate KIR3DL3 evolved as a conserved lineage distinct from other KIR. Accordingly, and in contrast to other KIR, we show the focus of natural selection does not correspond exclusively to known ligand binding sites. Instead, a strong signal for diversifying selection occurs in the D1 Ig domain at a site involved in receptor aggregation, which we show is polymorphic in humans worldwide, suggesting differential ability for receptor aggregation. Meanwhile in the cytoplasmic tail, the first of two inhibitory tyrosine motifs (ITIM) is conserved, whereas independent genomic events have mutated the second ITIM of KIR3DL3 alleles in all great apes. Together, these findings suggest that KIR3DL3 binds a conserved ligand, and a function requiring both receptor aggregation and inhibitory signal attenuation. In this model KIR3DL3 resembles other NK cell inhibitory receptors having only one ITIM, which interact with bivalent downstream signaling proteins through dimerization. Due to the extensive conservation across species, selection, and other unusual properties, we consider elucidating the ligand and function of KIR3DL3 to be a pressing question.


Assuntos
Heterozigoto , Primatas/genética , Primatas/metabolismo , Receptores KIR/genética , Receptores KIR/metabolismo , Transdução de Sinais , Sequência de Aminoácidos , Animais , Evolução Biológica , Hominidae , Humanos , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/metabolismo , Modelos Moleculares , Filogeografia , Primatas/imunologia , Ligação Proteica , Conformação Proteica , Domínios e Motivos de Interação entre Proteínas , Receptores KIR/química , Seleção Genética , Relação Estrutura-Atividade
16.
Nat Commun ; 10(1): 880, 2019 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-30787307

RESUMO

Asthma is a complex disease with striking disparities across racial and ethnic groups. Despite its relatively high burden, representation of individuals of African ancestry in asthma genome-wide association studies (GWAS) has been inadequate, and true associations in these underrepresented minority groups have been inconclusive. We report the results of a genome-wide meta-analysis from the Consortium on Asthma among African Ancestry Populations (CAAPA; 7009 asthma cases, 7645 controls). We find strong evidence for association at four previously reported asthma loci whose discovery was driven largely by non-African populations, including the chromosome 17q12-q21 locus and the chr12q13 region, a novel (and not previously replicated) asthma locus recently identified by the Trans-National Asthma Genetic Consortium (TAGC). An additional seven loci reported by TAGC show marginal evidence for association in CAAPA. We also identify two novel loci (8p23 and 8q24) that may be specific to asthma risk in African ancestry populations.


Assuntos
Afro-Americanos/genética , Asma/genética , Predisposição Genética para Doença/genética , Asma/epidemiologia , Cromossomos Humanos Par 12/genética , Cromossomos Humanos Par 17/genética , Cromossomos Humanos Par 8/genética , Loci Gênicos , Estudo de Associação Genômica Ampla , Hispano-Americanos/genética , Humanos , Polimorfismo de Nucleotídeo Único/genética , Estados Unidos/epidemiologia
17.
J Allergy Clin Immunol ; 143(3): 957-969, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30201514

RESUMO

BACKGROUND: Asthma is a common but complex disease with racial/ethnic differences in prevalence, morbidity, and response to therapies. OBJECTIVE: We sought to perform an analysis of genetic ancestry to identify new loci that contribute to asthma susceptibility. METHODS: We leveraged the mixed ancestry of 3902 Latinos and performed an admixture mapping meta-analysis for asthma susceptibility. We replicated associations in an independent study of 3774 Latinos, performed targeted sequencing for fine mapping, and tested for disease correlations with gene expression in the whole blood of more than 500 subjects from 3 racial/ethnic groups. RESULTS: We identified a genome-wide significant admixture mapping peak at 18q21 in Latinos (P = 6.8 × 10-6), where Native American ancestry was associated with increased risk of asthma (odds ratio [OR], 1.20; 95% CI, 1.07-1.34; P = .002) and European ancestry was associated with protection (OR, 0.86; 95% CI, 0.77-0.96; P = .008). Our findings were replicated in an independent childhood asthma study in Latinos (P = 5.3 × 10-3, combined P = 2.6 × 10-7). Fine mapping of 18q21 in 1978 Latinos identified a significant association with multiple variants 5' of SMAD family member 2 (SMAD2) in Mexicans, whereas a single rare variant in the same window was the top association in Puerto Ricans. Low versus high SMAD2 blood expression was correlated with case status (13.4% lower expression; OR, 3.93; 95% CI, 2.12-7.28; P < .001). In addition, lower expression of SMAD2 was associated with more frequent exacerbations among Puerto Ricans with asthma. CONCLUSION: Ancestry at 18q21 was significantly associated with asthma in Latinos and implicated multiple ancestry-informative noncoding variants upstream of SMAD2 with asthma susceptibility. Furthermore, decreased SMAD2 expression in blood was strongly associated with increased asthma risk and increased exacerbations.


Assuntos
Asma/genética , Cromossomos Humanos Par 18 , Predisposição Genética para Doença , Hispano-Americanos/genética , Proteína Smad2/genética , Mapeamento Cromossômico , Humanos , Polimorfismo de Nucleotídeo Único
18.
Clin Pharmacol Ther ; 105(5): 1256-1262, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30506572

RESUMO

The varying frequencies of pharmacogenetic alleles among populations have important implications for the impact of these alleles in different populations. Current population grouping methods to communicate these patterns are insufficient as they are inconsistent and fail to reflect the global distribution of genetic variability. To facilitate and standardize the reporting of variability in pharmacogenetic allele frequencies, we present seven geographically defined groups: American, Central/South Asian, East Asian, European, Near Eastern, Oceanian, and Sub-Saharan African, and two admixed groups: African American/Afro-Caribbean and Latino. These nine groups are defined by global autosomal genetic structure and based on data from large-scale sequencing initiatives. We recognize that broadly grouping global populations is an oversimplification of human diversity and does not capture complex social and cultural identity. However, these groups meet a key need in pharmacogenetics research by enabling consistent communication of the scale of variability in global allele frequencies and are now used by Pharmacogenomics Knowledgebase (PharmGKB).


Assuntos
Genética Populacional/métodos , Mapeamento Geográfico , Farmacogenética/métodos , Grupos Populacionais , Classificação , Frequência do Gene , Variação Genética , Humanos , Testes Farmacogenômicos , Grupos Populacionais/classificação , Grupos Populacionais/genética , Topografia Médica
19.
Proc Natl Acad Sci U S A ; 115(52): 13324-13329, 2018 12 26.
Artigo em Inglês | MEDLINE | ID: mdl-30530665

RESUMO

Skin pigmentation is under strong directional selection in northern European and Asian populations. The indigenous KhoeSan populations of far southern Africa have lighter skin than other sub-Saharan African populations, potentially reflecting local adaptation to a region of Africa with reduced UV radiation. Here, we demonstrate that a canonical Eurasian skin pigmentation gene, SLC24A5, was introduced to southern Africa via recent migration and experienced strong adaptive evolution in the KhoeSan. To reconstruct the evolution of skin pigmentation, we collected phenotypes from over 400 ≠Khomani San and Nama individuals and high-throughput sequenced candidate pigmentation genes. The derived causal allele in SLC24A5, p.Ala111Thr, significantly lightens basal skin pigmentation in the KhoeSan and explains 8 to 15% of phenotypic variance in these populations. The frequency of this allele (33 to 53%) is far greater than expected from colonial period European gene flow; however, the most common derived haplotype is identical among European, eastern African, and KhoeSan individuals. Using four-population demographic simulations with selection, we show that the allele was introduced into the KhoeSan only 2,000 y ago via a back-to-Africa migration and then experienced a selective sweep (s = 0.04 to 0.05 in ≠Khomani and Nama). The SLC24A5 locus is both a rare example of intense, ongoing adaptation in very recent human history, as well as an adaptive gene flow at a pigmentation locus in humans.


Assuntos
Antiporters/genética , Pigmentação da Pele/genética , Adulto , África Austral , Grupo com Ancestrais do Continente Africano/genética , Alelos , Antiporters/metabolismo , Grupo com Ancestrais do Continente Asiático/genética , Demografia/métodos , Grupo com Ancestrais do Continente Europeu/genética , Evolução Molecular , Feminino , Fluxo Gênico , Variação Genética/genética , Genética Populacional/métodos , Genótipo , Haplótipos , Humanos , Masculino , Fenótipo , Filogenia , Polimorfismo de Nucleotídeo Único/genética
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