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1.
Artigo em Inglês | MEDLINE | ID: mdl-34536413

RESUMO

BACKGROUND: Total serum IgE (tIgE) is an important intermediate phenotype of allergic disease. Whole genome genetic association studies across ancestries may identify important determinants of IgE. OBJECTIVE: By leveraging data from the NHLBI Trans-Omics for Precision Medicine (TOPMed) program, the Consortium on Asthma among African-ancestry Populations in the Americas (CAAPA) and the Atopic Dermatitis Research Network (ADRN), we aim to increase understanding of genetic variants affecting tIgE production across the ancestry and allergic disease spectrum (N=21,901). METHODS: We performed genome-wide association within strata of study, disease, and ancestry groups, and combined results via a meta-regression approach that models heterogeneity attributable to ancestry. We also tested for association between HLA alleles called from whole genome sequence data and tIgE, assessing replication of associations in HLA alleles called from genotype array data. For details, please see the Methods section in this article's Online Repository at www.jacionline.org. RESULTS: We identified six loci at genome-wide significance (P<5x10-9), including four loci previously reported as genome-wide significant for tIgE, as well as new regions in chr11q13.5 and chr15q22.2, also identified in prior GWAS of atopic dermatitis and asthma. In the HLA allele association study, HLA-A*02:01 was associated with decreased tIgE (discovery P = 2x10-4, replication P = 5x10-4, discovery+replication P=4x10-7) and HLA-DQB1*03:02 was strongly associated with decreased tIgE in Hispanic/Latino ancestry populations (Hispanic/Latino discovery+replication P=8x10-8). CONCLUSION: We performed the largest GWAS and HLA association study of tIgE focused on ancestrally diverse populations and found several known tIgE and allergic disease loci that are relevant in non-European ancestry populations.

2.
Am J Hum Genet ; 108(10): 1836-1851, 2021 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-34582791

RESUMO

Many common and rare variants associated with hematologic traits have been discovered through imputation on large-scale reference panels. However, the majority of genome-wide association studies (GWASs) have been conducted in Europeans, and determining causal variants has proved challenging. We performed a GWAS of total leukocyte, neutrophil, lymphocyte, monocyte, eosinophil, and basophil counts generated from 109,563,748 variants in the autosomes and the X chromosome in the Trans-Omics for Precision Medicine (TOPMed) program, which included data from 61,802 individuals of diverse ancestry. We discovered and replicated 7 leukocyte trait associations, including (1) the association between a chromosome X, pseudo-autosomal region (PAR), noncoding variant located between cytokine receptor genes (CSF2RA and CLRF2) and lower eosinophil count; and (2) associations between single variants found predominantly among African Americans at the S1PR3 (9q22.1) and HBB (11p15.4) loci and monocyte and lymphocyte counts, respectively. We further provide evidence indicating that the newly discovered eosinophil-lowering chromosome X PAR variant might be associated with reduced susceptibility to common allergic diseases such as atopic dermatitis and asthma. Additionally, we found a burden of very rare FLT3 (13q12.2) variants associated with monocyte counts. Together, these results emphasize the utility of whole-genome sequencing in diverse samples in identifying associations missed by European-ancestry-driven GWASs.

3.
Science ; 373(6558): 1030-1035, 2021 08 27.
Artigo em Inglês | MEDLINE | ID: mdl-34385354

RESUMO

Biological mechanisms underlying human germline mutations remain largely unknown. We statistically decompose variation in the rate and spectra of mutations along the genome using volume-regularized nonnegative matrix factorization. The analysis of a sequencing dataset (TOPMed) reveals nine processes that explain the variation in mutation properties between loci. We provide a biological interpretation for seven of these processes. We associate one process with bulky DNA lesions that are resolved asymmetrically with respect to transcription and replication. Two processes track direction of replication fork and replication timing, respectively. We identify a mutagenic effect of active demethylation primarily acting in regulatory regions and a mutagenic effect of long interspersed nuclear elements. We localize a mutagenic process specific to oocytes from population sequencing data. This process appears transcriptionally asymmetric.


Assuntos
Genoma Humano , Mutação em Linhagem Germinativa , Algoritmos , Ilhas de CpG , Dano ao DNA , Desmetilação do DNA , Análise Mutacional de DNA , Replicação do DNA , Variação Genética , Células Germinativas , Humanos , Elementos Nucleotídeos Longos e Dispersos , Mutagênese , Oócitos/fisiologia , Transcrição Genética
4.
Artigo em Inglês | MEDLINE | ID: mdl-34111454

RESUMO

BACKGROUND: While numerous genetic loci associated with atopic dermatitis (AD) have been discovered, to date, work leveraging the combined burden of AD risk variants across the genome to predict disease risk has been limited. OBJECTIVES: This study aims to determine whether polygenic risk scores (PRSs) relying on genetic determinants for AD provide useful predictions for disease occurrence and severity. It also explicitly tests the value of including genome-wide association studies of related allergic phenotypes and known FLG loss-of-function (LOF) variants. METHODS: AD PRSs were constructed for 1619 European American individuals from the Atopic Dermatitis Research Network using an AD training dataset and an atopic training dataset including AD, childhood onset asthma, and general allergy. Additionally, whole genome sequencing data were used to explore genetic scoring specific to FLG LOF mutations. RESULTS: Genetic scores derived from the AD-only genome-wide association studies were predictive of AD cases (PRSAD: odds ratio [OR], 1.70; 95% CI, 1.49-1.93). Accuracy was first improved when PRSs were built off the larger atopy genome-wide association studies (PRSAD+: OR, 2.16; 95% CI, 1.89-2.47) and further improved when including FLG LOF mutations (PRSAD++: OR, 3.23; 95% CI, 2.57-4.07). Importantly, while all 3 PRSs correlated with AD severity, the best prediction was from PRSAD++, which distinguished individuals with severe AD from control subjects with OR of 3.86 (95% CI, 2.77-5.36). CONCLUSIONS: This study demonstrates how PRSs for AD that include genetic determinants across atopic phenotypes and FLG LOF variants may be a promising tool for identifying individuals at high risk for developing disease and specifically severe disease.

5.
Am J Epidemiol ; 190(10): 1977-1992, 2021 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-33861317

RESUMO

Genotype-phenotype association studies often combine phenotype data from multiple studies to increase statistical power. Harmonization of the data usually requires substantial effort due to heterogeneity in phenotype definitions, study design, data collection procedures, and data-set organization. Here we describe a centralized system for phenotype harmonization that includes input from phenotype domain and study experts, quality control, documentation, reproducible results, and data-sharing mechanisms. This system was developed for the National Heart, Lung, and Blood Institute's Trans-Omics for Precision Medicine (TOPMed) program, which is generating genomic and other -omics data for more than 80 studies with extensive phenotype data. To date, 63 phenotypes have been harmonized across thousands of participants (recruited in 1948-2012) from up to 17 studies per phenotype. Here we discuss challenges in this undertaking and how they were addressed. The harmonized phenotype data and associated documentation have been submitted to National Institutes of Health data repositories for controlled access by the scientific community. We also provide materials to facilitate future harmonization efforts by the community, which include 1) the software code used to generate the 63 harmonized phenotypes, enabling others to reproduce, modify, or extend these harmonizations to additional studies, and 2) the results of labeling thousands of phenotype variables with controlled vocabulary terms.

6.
Genetics ; 218(1)2021 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-33720349

RESUMO

Traditional Hardy-Weinberg equilibrium (HWE) tests (the χ2 test and the exact test) have long been used as a metric for evaluating genotype quality, as technical artifacts leading to incorrect genotype calls often can be identified as deviations from HWE. However, in data sets composed of individuals from diverse ancestries, HWE can be violated even without genotyping error, complicating the use of HWE testing to assess genotype data quality. In this manuscript, we present the Robust Unified Test for HWE (RUTH) to test for HWE while accounting for population structure and genotype uncertainty, and to evaluate the impact of population heterogeneity and genotype uncertainty on the standard HWE tests and alternative methods using simulated and real sequence data sets. Our results demonstrate that ignoring population structure or genotype uncertainty in HWE tests can inflate false-positive rates by many orders of magnitude. Our evaluations demonstrate different tradeoffs between false positives and statistical power across the methods, with RUTH consistently among the best across all evaluations. RUTH is implemented as a practical and scalable software tool to rapidly perform HWE tests across millions of markers and hundreds of thousands of individuals while supporting standard VCF/BCF formats. RUTH is publicly available at https://www.github.com/statgen/ruth.

7.
Artigo em Inglês | MEDLINE | ID: mdl-33713768

RESUMO

BACKGROUND: Genetic ancestry plays a role in asthma health disparities. OBJECTIVE: Our aim was to evaluate the impact of ancestry on and identify genetic variants associated with asthma, total serum IgE level, and lung function. METHODS: A total of 436 Peruvian children (aged 9-19 years) with asthma and 291 without asthma were genotyped by using the Illumina Multi-Ethnic Global Array. Genome-wide proportions of indigenous ancestry populations from continental America (NAT) and European ancestry from the Iberian populations in Spain (IBS) were estimated by using ADMIXTURE. We assessed the relationship between ancestry and the phenotypes and performed a genome-wide association study. RESULTS: The mean ancestry proportions were 84.7% NAT (case patients, 84.2%; controls, 85.4%) and 15.3% IBS (15.8%; 14.6%). With adjustment for asthma, NAT was associated with higher total serum IgE levels (P < .001) and IBS was associated with lower total serum IgE levels (P < .001). NAT was associated with higher FEV1 percent predicted values (P < .001), whereas IBS was associated with lower FEV1 values in the controls but not in the case patients. The HLA-DR/DQ region on chromosome 6 (Chr6) was strongly associated with total serum IgE (rs3135348; P = 3.438 × 10-10) and was independent of an association with the haplotype HLA-DQA1∼HLA-DQB1:04.01∼04.02 (P = 1.55 × 10-05). For lung function, we identified a locus (rs4410198; P = 5.536 × 10-11) mapping to Chr19, near a cluster of zinc finger interacting genes that colocalizes to the long noncoding RNA CTD-2537I9.5. This novel locus was replicated in an independent sample of pediatric case patients with asthma with similar admixture from Brazil (P = .005). CONCLUSION: This study confirms the role of HLA in atopy, and identifies a novel locus mapping to a long noncoding RNA for lung function that may be specific to children with NAT.

9.
Allergy ; 76(8): 2510-2523, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33548076

RESUMO

BACKGROUND: Eczema herpeticum (EH) is a rare complication of atopic dermatitis (AD) caused by disseminated herpes simplex virus (HSV) infection. The role of rare and/or deleterious genetic variants in disease etiology is largely unknown. This study aimed to identify genes that harbor damaging genetic variants associated with HSV infection in AD with a history of recurrent eczema herpeticum (ADEH+). METHODS: Whole genome sequencing (WGS) was performed on 49 recurrent ADEH+ (≥3 EH episodes), 491 AD without a history of eczema herpeticum (ADEH-) and 237 non-atopic control (NA) subjects. Variants were annotated, and a gene-based approach (SKAT-O) was used to identify genes harboring damaging genetic variants associated with ADEH+. Genes identified through WGS were studied for effects on HSV responses and keratinocyte differentiation. RESULTS: Eight genes were identified in the comparison of recurrent ADEH+to ADEH-and NA subjects: SIDT2, CLEC7A, GSTZ1, TPSG1, SP110, RBBP8NL, TRIM15, and FRMD3. Silencing SIDT2 and RBBP8NL in normal human primary keratinocytes (NHPKs) led to significantly increased HSV-1 replication. SIDT2-silenced NHPKs had decreased gene expression of IFNk and IL1b in response to HSV-1 infection. RBBP8NL-silenced NHPKs had decreased gene expression of IFNk, but increased IL1b. Additionally, silencing SIDT2 and RBBP8NL also inhibited gene expression of keratinocyte differentiation markers keratin 10 (KRT10) and loricrin (LOR). CONCLUSION: SIDT2 and RBBP8NL participate in keratinocyte's response to HSV-1 infection. SIDT2 and RBBP8NL also regulate expression of keratinocyte differentiation genes of KRT10 and LOR.


Assuntos
Dermatite Atópica , Herpesvirus Humano 1 , Erupção Variceliforme de Kaposi , Proteínas de Transporte de Nucleotídeos , Dermatite Atópica/genética , Glutationa Transferase , Herpesvirus Humano 1/genética , Humanos , Erupção Variceliforme de Kaposi/genética , Mutação , Sequenciamento Completo do Genoma
10.
J Genet Couns ; 30(1): 257-267, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32951257

RESUMO

The number of institutional and governmental biobanks and the target enrollment sizes of modern biobanks are increasing, affording more opportunities for the public to participate in biobanking efforts. In parallel with these expansions are pressures to increase the efficiency of obtaining informed consent using shorter consent forms that cover a broader scope of research and increasingly include provisions for return of research or clinical genetic test results to participants. Given these changes, how well these participants understand genetics, their level of understanding of what they are consenting to, and their wishes to engage longitudinally and receive biobank results are not well understood. We surveyed participants in a large, medical system-based biobank who had enrolled through a two-page, self-consent process about their baseline knowledge of genetics, understanding and recall of the consent process, wishes for future contact and engagement, and level of interest in receiving clinical genetic testing results. A total of 856 consented persons participated in the survey (67% women; 67% white). Participants' general reported genetics knowledge was relatively high (mean 11.60 of 15 questions answered correctly) as was recall of key elements from the two-page consent form. Overall participant enthusiasm for future contact by the biobank and for receiving clinical genetic testing results was high. The use of a two-page, self-consent process in a large, institutional biobank resulted in high levels of consent recall and enthusiasm for future ongoing engagement and receipt of genetic testing results by participants.

11.
Nat Commun ; 11(1): 6417, 2020 12 18.
Artigo em Inglês | MEDLINE | ID: mdl-33339817

RESUMO

Pharmaceutical drugs targeting dyslipidemia and cardiovascular disease (CVD) may increase the risk of fatty liver disease and other metabolic disorders. To identify potential novel CVD drug targets without these adverse effects, we perform genome-wide analyses of participants in the HUNT Study in Norway (n = 69,479) to search for protein-altering variants with beneficial impact on quantitative blood traits related to cardiovascular disease, but without detrimental impact on liver function. We identify 76 (11 previously unreported) presumed causal protein-altering variants associated with one or more CVD- or liver-related blood traits. Nine of the variants are predicted to result in loss-of-function of the protein. This includes ZNF529:p.K405X, which is associated with decreased low-density-lipoprotein (LDL) cholesterol (P = 1.3 × 10-8) without being associated with liver enzymes or non-fasting blood glucose. Silencing of ZNF529 in human hepatoma cells results in upregulation of LDL receptor and increased LDL uptake in the cells. This suggests that inhibition of ZNF529 or its gene product should be prioritized as a novel candidate drug target for treating dyslipidemia and associated CVD.


Assuntos
Doenças Cardiovasculares/genética , Genoma Humano , Mutação com Perda de Função/genética , Terapia de Alvo Molecular , Bancos de Espécimes Biológicos , Doenças Cardiovasculares/sangue , Inativação Gênica , Marcação de Genes , Estudo de Associação Genômica Ampla , Humanos , Lipídeos/sangue , Fígado/metabolismo , Fenômica , Receptores de LDL/genética , Reino Unido
12.
Nat Commun ; 11(1): 5182, 2020 10 14.
Artigo em Inglês | MEDLINE | ID: mdl-33057025

RESUMO

Chronic obstructive pulmonary disease (COPD), diagnosed by reduced lung function, is a leading cause of morbidity and mortality. We performed whole genome sequence (WGS) analysis of lung function and COPD in a multi-ethnic sample of 11,497 participants from population- and family-based studies, and 8499 individuals from COPD-enriched studies in the NHLBI Trans-Omics for Precision Medicine (TOPMed) Program. We identify at genome-wide significance 10 known GWAS loci and 22 distinct, previously unreported loci, including two common variant signals from stratified analysis of African Americans. Four novel common variants within the regions of PIAS1, RGN (two variants) and FTO show evidence of replication in the UK Biobank (European ancestry n ~ 320,000), while colocalization analyses leveraging multi-omic data from GTEx and TOPMed identify potential molecular mechanisms underlying four of the 22 novel loci. Our study demonstrates the value of performing WGS analyses and multi-omic follow-up in cohorts of diverse ancestry.


Assuntos
Afro-Americanos/genética , Loci Gênicos , Doença Pulmonar Obstrutiva Crônica/genética , Fenômenos Fisiológicos Respiratórios/genética , Sequenciamento Completo do Genoma , Adulto , Idoso , Idoso de 80 Anos ou mais , Dioxigenase FTO Dependente de alfa-Cetoglutarato/genética , Proteínas de Ligação ao Cálcio/genética , Estudos de Viabilidade , Feminino , Seguimentos , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Pulmão/fisiopatologia , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Proteínas Inibidoras de STAT Ativados/genética , Doença Pulmonar Obstrutiva Crônica/etnologia , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Proteínas Modificadoras Pequenas Relacionadas à Ubiquitina/genética
13.
Nature ; 586(7831): 763-768, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-33057201

RESUMO

Age is the dominant risk factor for most chronic human diseases, but the mechanisms through which ageing confers this risk are largely unknown1. The age-related acquisition of somatic mutations that lead to clonal expansion in regenerating haematopoietic stem cell populations has recently been associated with both haematological cancer2-4 and coronary heart disease5-this phenomenon is termed clonal haematopoiesis of indeterminate potential (CHIP)6. Simultaneous analyses of germline and somatic whole-genome sequences provide the opportunity to identify root causes of CHIP. Here we analyse high-coverage whole-genome sequences from 97,691 participants of diverse ancestries in the National Heart, Lung, and Blood Institute Trans-omics for Precision Medicine (TOPMed) programme, and identify 4,229 individuals with CHIP. We identify associations with blood cell, lipid and inflammatory traits that are specific to different CHIP driver genes. Association of a genome-wide set of germline genetic variants enabled the identification of three genetic loci associated with CHIP status, including one locus at TET2 that was specific to individuals of African ancestry. In silico-informed in vitro evaluation of the TET2 germline locus enabled the identification of a causal variant that disrupts a TET2 distal enhancer, resulting in increased self-renewal of haematopoietic stem cells. Overall, we observe that germline genetic variation shapes haematopoietic stem cell function, leading to CHIP through mechanisms that are specific to clonal haematopoiesis as well as shared mechanisms that lead to somatic mutations across tissues.


Assuntos
Hematopoiese Clonal/genética , Predisposição Genética para Doença , Genoma Humano/genética , Sequenciamento Completo do Genoma , Adulto , África/etnologia , Grupo com Ancestrais do Continente Africano/genética , Idoso , Idoso de 80 Anos ou mais , Autorrenovação Celular/genética , Proteínas de Ligação a DNA/genética , Feminino , Mutação em Linhagem Germinativa/genética , Células-Tronco Hematopoéticas/citologia , Células-Tronco Hematopoéticas/metabolismo , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Masculino , Pessoa de Meia-Idade , National Heart, Lung, and Blood Institute (U.S.) , Fenótipo , Medicina de Precisão , Proteínas Proto-Oncogênicas/genética , Proteínas com Motivo Tripartido/genética , Estados Unidos , alfa Carioferinas/genética
14.
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
15.
Lancet Respir Med ; 8(7): 696-708, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32649918

RESUMO

BACKGROUND: Genetic factors influence chronic obstructive pulmonary disease (COPD) risk, but the individual variants that have been identified have small effects. We hypothesised that a polygenic risk score using additional variants would predict COPD and associated phenotypes. METHODS: We constructed a polygenic risk score using a genome-wide association study of lung function (FEV1 and FEV1/forced vital capacity [FVC]) from the UK Biobank and SpiroMeta. We tested this polygenic risk score in nine cohorts of multiple ethnicities for an association with moderate-to-severe COPD (defined as FEV1/FVC <0·7 and FEV1 <80% of predicted). Associations were tested using logistic regression models, adjusting for age, sex, height, smoking pack-years, and principal components of genetic ancestry. We assessed predictive performance of models by area under the curve. In a subset of studies, we also studied quantitative and qualitative CT imaging phenotypes that reflect parenchymal and airway pathology, and patterns of reduced lung growth. FINDINGS: The polygenic risk score was associated with COPD in European (odds ratio [OR] per SD 1·81 [95% CI 1·74-1·88] and non-European (1·42 [1·34-1·51]) populations. Compared with the first decile, the tenth decile of the polygenic risk score was associated with COPD, with an OR of 7·99 (6·56-9·72) in European ancestry and 4·83 (3·45-6·77) in non-European ancestry cohorts. The polygenic risk score was superior to previously described genetic risk scores and, when combined with clinical risk factors (ie, age, sex, and smoking pack-years), showed improved prediction for COPD compared with a model comprising clinical risk factors alone (AUC 0·80 [0·79-0·81] vs 0·76 [0·75-0·76]). The polygenic risk score was associated with CT imaging phenotypes, including wall area percent, quantitative and qualitative measures of emphysema, local histogram emphysema patterns, and destructive emphysema subtypes. The polygenic risk score was associated with a reduced lung growth pattern. INTERPRETATION: A risk score comprised of genetic variants can identify a small subset of individuals at markedly increased risk for moderate-to-severe COPD, emphysema subtypes associated with cigarette smoking, and patterns of reduced lung growth. FUNDING: US National Institutes of Health, Wellcome Trust.


Assuntos
Doença Pulmonar Obstrutiva Crônica/epidemiologia , Doença Pulmonar Obstrutiva Crônica/genética , Adulto , Estudos de Casos e Controles , Estudos de Coortes , Feminino , Volume Expiratório Forçado , Estudo de Associação Genômica Ampla , Humanos , Masculino , Pessoa de Meia-Idade , Fenótipo , Doença Pulmonar Obstrutiva Crônica/diagnóstico , Fatores de Risco , Capacidade Vital
16.
Stat Methods Med Res ; 29(11): 3153-3165, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32393154

RESUMO

The case-control study design is one of the main tools for detecting associations between genetic markers and diseases. It is well known that population substructure can lead to spurious association between disease status and a genetic marker if the prevalence of disease and the marker allele frequency vary across subpopulations. In this paper, we propose a novel statistical method to estimate the association in case-control studies with unmeasured population substructure. The proposed method takes two steps. First, the information on genomic markers and disease status is used to infer the population substructure; second, the association between the disease and the test marker adjusting for the population substructure is modeled and estimated parametrically through polytomous logistic regression. The performance of the proposed method, relative to the existing methods, on bias, coverage probability and computational time, is assessed through simulations. The method is applied to an end-stage renal disease study in African Americans population.

17.
Pharmacogenomics ; 21(6): 375-386, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32077359

RESUMO

In recent years, the genomics community has witnessed the growth of large research biobanks, which collect DNA samples for research purposes. Depending on how and where the samples are genotyped, biobanks also offer the potential opportunity to return actionable genomic results to the clinical setting. We developed a preemptive clinical pharmacogenomic implementation initiative via a health system-wide research biobank at the University of Colorado. Here, we describe how preemptive return of clinical pharmacogenomic results via a research biobank is feasible, particularly when coupled with strong institutional support to maximize the impact and efficiency of biobank resources, a multidisciplinary implementation team, automated clinical decision support tools, and proactive strategies to engage stakeholders early in the clinical decision support tool development process.


Assuntos
Centros Médicos Acadêmicos/tendências , Bancos de Espécimes Biológicos/tendências , Sistemas de Apoio a Decisões Clínicas/tendências , Farmacogenética/tendências , Medicina de Precisão/tendências , Centros Médicos Acadêmicos/métodos , Colorado/epidemiologia , Citocromo P-450 CYP2C19/genética , Humanos , Farmacogenética/métodos , Medicina de Precisão/métodos
18.
Proc Natl Acad Sci U S A ; 117(5): 2560-2569, 2020 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-31964835

RESUMO

De novo mutations (DNMs), or mutations that appear in an individual despite not being seen in their parents, are an important source of genetic variation whose impact is relevant to studies of human evolution, genetics, and disease. Utilizing high-coverage whole-genome sequencing data as part of the Trans-Omics for Precision Medicine (TOPMed) Program, we called 93,325 single-nucleotide DNMs across 1,465 trios from an array of diverse human populations, and used them to directly estimate and analyze DNM counts, rates, and spectra. We find a significant positive correlation between local recombination rate and local DNM rate, and that DNM rate explains a substantial portion (8.98 to 34.92%, depending on the model) of the genome-wide variation in population-level genetic variation from 41K unrelated TOPMed samples. Genome-wide heterozygosity does correlate with DNM rate, but only explains <1% of variation. While we are underpowered to see small differences, we do not find significant differences in DNM rate between individuals of European, African, and Latino ancestry, nor across ancestrally distinct segments within admixed individuals. However, we did find significantly fewer DNMs in Amish individuals, even when compared with other Europeans, and even after accounting for parental age and sequencing center. Specifically, we found significant reductions in the number of C→A and T→C mutations in the Amish, which seem to underpin their overall reduction in DNMs. Finally, we calculated near-zero estimates of narrow sense heritability (h 2), which suggest that variation in DNM rate is significantly shaped by nonadditive genetic effects and the environment.


Assuntos
Amish/genética , Genoma Humano , Adulto , Estudos de Coortes , Análise Mutacional de DNA , Feminino , Genética Populacional , Heterozigoto , Humanos , Masculino , Mutação , Linhagem , Sequenciamento Completo do Genoma , Adulto Jovem
19.
J Allergy Clin Immunol ; 146(1): 147-155, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-31981624

RESUMO

BACKGROUND: Asthma is a complex chronic inflammatory disease of the airways. Association studies between HLA and asthma were first reported in the 1970s, and yet, the precise role of HLA alleles in asthma is not fully understood. Numerous genome-wide association studies were recently conducted on asthma, but were always limited to simple genetic markers (single nucleotide polymorphisms) and not complex HLA gene polymorphisms (alleles/haplotypes), therefore not capturing the biological relevance of this complex locus for asthma pathogenesis. OBJECTIVE: To run the first HLA-centric association study with asthma and specific asthma-related phenotypes in a large cohort of African-ancestry individuals. METHODS: We collected high-density genomics data for the Consortium on Asthma among African-ancestry Populations in the Americas (N = 4993) participants. Using computer-intensive machine-learning attribute bagging methods to infer HLA alleles, and Easy-HLA to infer HLA 5-gene haplotypes, we conducted a high-throughput HLA-centric association study of asthma susceptibility and total serum IgE (tIgE) levels in subjects with and without asthma. RESULTS: Among the 1607 individuals with asthma, 972 had available tIgE levels, with a mean tIgE level of 198.7 IU/mL. We could not identify any association with asthma susceptibility. However, we showed that HLA-DRB1∗09:01 was associated with increased tIgE levels (P = 8.5 × 10-4; weighted effect size, 0.51 [0.15-0.87]). CONCLUSIONS: We identified for the first time an HLA allele associated with tIgE levels in African-ancestry individuals with asthma. Our report emphasizes that by leveraging powerful computational machine-learning methods, specific/extreme phenotypes, and population diversity, we can explore HLA gene polymorphisms in depth and reveal the full extent of complex disease associations.


Assuntos
Afro-Americanos/genética , Alelos , Cadeias HLA-DRB1/genética , Imunoglobulina E/imunologia , Polimorfismo de Nucleotídeo Único , Asma , Feminino , Cadeias HLA-DRB1/imunologia , Humanos , Masculino
20.
Bioinformatics ; 36(7): 2157-2164, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-31750874

RESUMO

MOTIVATION: The HLA system plays a pivotal role in both clinical applications and immunology research. Typing HLA genes in patient and donor is indeed required in hematopoietic stem cell and solid-organ transplantation, and the histocompatibility complex region exhibits countless genetic associations with immune-related pathologies. Since the discovery of HLA antigens, the HLA system nomenclature and typing methods have constantly evolved, which leads to difficulties in using data generated with older methodologies. RESULTS: Here, we present Easy-HLA, a web-based software suite designed to facilitate analysis and gain knowledge from HLA typing, regardless of nomenclature or typing method. Easy-HLA implements a computational and statistical method of HLA haplotypes inference based on published reference populations containing over 600 000 haplotypes to upgrade missing or partial HLA information: 'HLA-Upgrade' tool infers high-resolution HLA typing and 'HLA-2-Haplo' imputes haplotype pairs and provides additional functional annotations (e.g. amino acids and KIR ligands). We validated both tools using two independent cohorts (total n = 2500). For HLA-Upgrade, we reached a prediction accuracy of 92% from low- to high-resolution of European genotypes. We observed a 96% call rate and 76% accuracy with HLA-2-Haplo European haplotype pairs prediction. In conclusion, Easy-HLA tools facilitate large-scale immunogenetic analysis and promotes the multi-faceted HLA expertise beyond allelic associations by providing new functional immunogenomics parameters. AVAILABILITY AND IMPLEMENTATION: Easy-HLA is a web application freely available (free account) at: https://hla.univ-nantes.fr. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Assuntos
Antígenos HLA , Alelos , Genótipo , Haplótipos , Teste de Histocompatibilidade , Humanos
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