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1.
Am J Epidemiol ; 2019 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-31509181

RESUMO

The field of genetic epidemiology is relatively young and brings together genetics, epidemiology and biostatistics to identify and implement the best study designs and statistical analyses for identifying genes controlling risk to complex and heterogeneous diseases (i.e. those where genes and environmental risk factors both contribute to etiology). The field has moved quickly over the past 40 years partly because the technology of genotyping and sequencing has forced it to adapt while adhering to the fundamental principles of genetics. In the last two decades, the available tools for genetic epidemiology have expanded from a genetic focus (i.e. considering one gene at a time) to a genomic focus (i.e. considering the entire genome), and now they must further expand to integrate information from other "-omics" (e.g. epigenomics, transcriptomics as measured by RNA expression) both at the individual level and at the population level. Additionally, we can now also evaluate gene and environmental interactions across populations to better understand exposure and the heterogeneity in disease risk. The future challenges facing genetic epidemiology are considerable both in scale and techniques, but the importance of the field will not diminish because by design it ties scientific goals with public health applications.

2.
Clin Epigenetics ; 11(1): 122, 2019 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-31443688

RESUMO

BACKGROUND: Although epigenetic mechanisms are important risk factors for allergic disease, few studies have evaluated DNA methylation differences associated with atopic dermatitis (AD), and none has focused on AD with eczema herpeticum (ADEH+). We will determine how methylation varies in AD individuals with/without EH and associated traits. We modeled differences in genome-wide DNA methylation in whole blood cells from 90 ADEH+, 83 ADEH-, and 84 non-atopic, healthy control subjects, replicating in 36 ADEH+, 53 ADEH-, and 55 non-atopic healthy control subjects. We adjusted for cell-type composition in our models and used genome-wide and candidate-gene approaches. RESULTS: We replicated one CpG which was significantly differentially methylated by severity, with suggestive replication at four others showing differential methylation by phenotype or severity. Not adjusting for eosinophil content, we identified 490 significantly differentially methylated CpGs (ADEH+ vs healthy controls, genome-wide). Many of these associated with severity measures, especially eosinophil count (431/490 sites). CONCLUSIONS: We identified a CpG in IL4 associated with serum tIgE levels, supporting a role for Th2 immune mediating mechanisms in AD. Changes in eosinophil level, a measure of disease severity, are associated with methylation changes, providing a potential mechanism for phenotypic changes in immune response-related traits.

3.
Mol Genet Genomic Med ; : e872, 2019 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-31419083

RESUMO

BACKGROUND: Nonsyndromic cleft lip with or without cleft palate (NSCL/P) is a common birth defect with complex etiology. One strategy for studying the genetic risk factors of NSCL/P is to consider gene-gene interaction (G × G) among gene pathways having a role in craniofacial development. The present study aimed to investigate the G × G among cell adhesion gene pathway. METHODS: We carried out an interaction analysis of eight genes involved in cell adherens junctions among 806 NSCL/P Chinese case-parent trios originally recruited for a genome-wide association study (GWAS). Regression-based approach was used to test for two-way G × G interaction, while machine learning algorithm was run for exploring both two-way and multi-way interaction that may affect the risk of NSCL/P. RESULTS: A two-way ACTN1 × CTNNB1 interaction reached the adjusted significance level. The single nucleotide polymorphisms pair composed of rs17252114 (CTNNB1) and rs1274944 (ACTN1) yielded a p value of .0002, and this interaction was also supported by the logic regression algorithm. Higher order interactions involving ACTN1, CTNNB1, and CDH1 were picked out by logic regression, suggesting a potential role in NSCL/P risk. CONCLUSION: This study suggests for the first time evidence of both two-way and multi-way G × G interactions among cell adhesion genes contributing to the NSCL/P risk.

4.
PLoS Genet ; 15(7): e1008229, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31269066

RESUMO

While many disease-associated single nucleotide polymorphisms (SNPs) are associated with gene expression (expression quantitative trait loci, eQTLs), a large proportion of complex disease genome-wide association study (GWAS) variants are of unknown function. Some of these SNPs may contribute to disease by regulating gene splicing. Here, we investigate whether SNPs that are associated with alternative splicing (splice QTL or sQTL) can identify novel functions for existing GWAS variants or suggest new associated variants in chronic obstructive pulmonary disease (COPD). RNA sequencing was performed on whole blood from 376 subjects from the COPDGene Study. Using linear models, we identified 561,060 unique sQTL SNPs associated with 30,333 splice sites corresponding to 6,419 unique genes. Similarly, 708,928 unique eQTL SNPs involving 15,913 genes were detected at 10% FDR. While there is overlap between sQTLs and eQTLs, 55.3% of sQTLs are not eQTLs. Co-localization analysis revealed that 7 out of 21 loci associated with COPD (p<1x10-6) in a published GWAS have at least one shared causal variant between the GWAS and sQTL studies. Among the genes identified to have splice sites associated with top GWAS SNPs was FBXO38, in which a novel exon was discovered to be protective against COPD. Importantly, the sQTL in this locus was validated by qPCR in both blood and lung tissue, demonstrating that splice variants relevant to lung tissue can be identified in blood. Other identified genes included CDK11A and SULT1A2. Overall, these data indicate that analysis of alternative splicing can provide novel insights into disease mechanisms. In particular, we demonstrated that SNPs in a known COPD GWAS locus on chromosome 5q32 influence alternative splicing in the gene FBXO38.

5.
Respir Res ; 20(1): 160, 2019 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-31324189

RESUMO

BACKGROUND: Emphysema, characterized by lung destruction, is a key component of Chronic Obstructive Pulmonary Disease (COPD) and is associated with increased morbidity and mortality. Genome-wide association studies (GWAS) have identified multiple genetic factors associated with cross-sectional measures of quantitative emphysema, but the genetic determinants of longitudinal change in quantitative measures of emphysema remain largely unknown. Our study aims to identify genetic variants associated with longitudinal change in quantitative emphysema measured by computed tomography (CT) imaging. METHODS: We included current and ex-smokers from two longitudinal cohorts: COPDGene, a study of Non-Hispanic Whites (NHW) and African Americans (AA), and the Evaluation of COPD Longitudinally to Identify Predictive Surrogate End-points (ECLIPSE). We calculated annual change in two quantitative measures of emphysema based on chest CT imaging: percent low attenuation area (≤ - 950HU) (%LAA-950) and adjusted lung density (ALD). We conducted GWAS, separately in 3030 NHW and 1158 AA from COPDGene and 1397 Whites from ECLIPSE. We further explored effects of 360 previously reported variants and a lung function based polygenic risk score on annual change in quantitative emphysema. RESULTS: In the genome-wide association analysis, no variants achieved genome-wide significance (P < 5e-08). However, in the candidate region analysis, rs2076295 in the DSP gene, previously associated with COPD, lung function and idiopathic pulmonary fibrosis, was associated with change in %LAA-950 (ß (SE) = 0.09 (0.02), P = 3.79e-05) and in ALD (ß (SE) = - 0.06 (0.02), P = 2.88e-03). A lung function based polygenic risk score was associated with annual change in %LAA-950 (P = 4.03e-02) and with baseline measures of quantitative emphysema (P < 1e-03) and showed a trend toward association with annual change in ALD (P = 7.31e-02). CONCLUSIONS: DSP variants may be associated with longitudinal change in quantitative emphysema. Additional investigation of the DSP gene are likely to provide further insights into the disease progression in emphysema and COPD. TRIAL REGISTRATION: Clinicaltrials.gov Identifier: NCT00608764 , NCT00292552 .

6.
Genet Epidemiol ; 43(6): 704-716, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31172578

RESUMO

Phenotypic heterogeneity is a hallmark of complex traits, and genetic studies of such traits may focus on them as a single diagnostic entity or by analyzing specific components. For example, in orofacial clefting (OFC), three subtypes-cleft lip (CL), cleft lip and palate (CLP), and cleft palate (CP) have been studied separately and in combination. To further dissect the genetic architecture of OFCs and how a given associated locus may be contributing to distinct subtypes of a trait we developed a framework for quantifying and interpreting evidence of subtype-specific or shared genetic effects in complex traits. We applied this technique to create a "cleft map" of the association of 30 genetic loci with three OFC subtypes. In addition to new associations, we found loci with subtype-specific effects (e.g., GRHL3 [CP], WNT5A [CLP]), as well as loci associated with two or all three subtypes. We cross-referenced these results with mouse craniofacial gene expression datasets, which identified additional promising candidate genes. However, we found no strong correlation between OFC subtypes and expression patterns. In aggregate, the cleft map revealed that neither subtype-specific nor shared genetic effects operate in isolation in OFC architecture. Our approach can be easily applied to any complex trait with distinct phenotypic subgroups.

8.
Community Dent Oral Epidemiol ; 47(4): 283-290, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30993747

RESUMO

OBJECTIVES: Dental utilization is an important determinant of oral health and well-being. The aim of this study was to evaluate potential associations between a variety of biopsychosocial factors and dental utilization in north-central Appalachia, USA, a region where oral health disparities are profound. METHODS: This study used household-based data from the Center for Oral Health Research in Appalachia (COHRA1) study in north-central Appalachia, including 449 families with 868 adults. The generalized estimating equation (GEE) approach was used to determine the best-fitting predictor model for dental utilization among adult family members. RESULTS: On average across West Virginia and Pennsylvania, having dental insurance was associated with greater dental utilization over a 3-year time period (OR = 2.20, 95% CI = 1.54, 3.14). When stratified by state, the association held for only West Virginia (OR = 2.41, 95% CI = 1.54, 3.79) and was nonsignificant for Pennsylvania residents (OR = 1.50, 95% CI = 0.80, 2.79). Individuals from Pennsylvania were more likely to utilize dental care and participants from West Virginia less so (2.31, 95% CI = 1.57, 3.40). Females from Pennsylvania were more likely than males to regularly seek dental care (OR = 1.44, 95% CI = 1.00, 2.05), and a higher income was associated with greater frequency of regular dental visits (OR = 1.21, 95% CI = 1.09, 1.34) in West Virginia. Individuals from Pennsylvania who scored higher on the Physiological Arousal subscale of the Dental Fear Survey were more likely to attend routine care visits (OR = 1.18, 95% CI = 1.03, 1.35). Across both states, more fatalistic beliefs related to oral health care also predicted less routine care (OR = 0.87, 95% CI = 0.81, 0.94), and more investment in or more positive attitudes towards one's oral health also was associated with higher utilization (OR = 1.18, 95% CI = 1.13, 1.23). CONCLUSIONS: Overall, the findings of this study suggest state residency, sex, insurance, income, fatalistic beliefs, health values, and aspects of dental care-related anxiety and fear predicted dental care utilization in north-central Appalachia. These findings reinforce the need to address insurance and other economic factors affecting utilization and to consider how individual-level fatalistic beliefs and oral health values may affect utilization of routine oral health care.

9.
Artigo em Inglês | MEDLINE | ID: mdl-30908940

RESUMO

Chronic obstructive pulmonary disease (COPD) is a common and progressive disease that is influenced by both genetic and environmental factors. For many years, knowledge of the genetic basis of COPD was limited to Mendelian syndromes, such as alpha-1 antitrypsin deficiency and cutis laxa, caused by rare genetic variants. Fortunately, over the past decade, the proliferation of genome-wide association studies (GWAS), the accessibility of whole genome sequencing, and the development of novel methods for analyzing genetic variation data have led to a substantial increase in our understanding of genetic variants that play a role in COPD susceptibility and COPD-related phenotypes. COPDGene, a multicenter, longitudinal study of over 10,000 current and former cigarette smokers, has been pivotal to these breakthroughs in understanding the genetic basis of COPD. To date, over 20 genetic loci have been convincingly associated with COPD affection status, with additional loci demonstrating association with COPD-related phenotypes such as emphysema, chronic bronchitis, and hypoxemia. In this review, we discuss the contributions of the COPDGene study to the discovery of these genetic associations as well as the ongoing genetic investigations of COPD subtypes, protein biomarkers, and post-GWAS analysis.

10.
Environ Mol Mutagen ; 60(7): 602-606, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30848863

RESUMO

Nonsyndromic cleft lip with or without cleft palate (NSCL/P) is a common birth defect. Genetic variants causing syndromic orofacial clefts can also contribute to the etiology of NSCL/P. The purpose of the present study was to explore gene-gene (G × G) interaction using common single nucleotide polymorphic (SNP) markers in fibroblast growth factor (FGF) family and its receptors and T-box genes, which were associated with syndromic orofacial clefts. Our study was conducted in 806 Chinese NSCL/P case-parent trios drawn from an international consortium. A total of 252 SNPs in FGF8, FGF10, FGFR1, FGFR2, and TBX5 passed the quality control criteria and were included in the analysis. The interactions between SNPs in different genes were assessed using Cordell's method, which fitted a conditional logistic regression model. The analysis was performed using the R-package trio (Version 3.8.0). Bonferroni correction was used to adjust for multiple comparisons, and the overall significance threshold was set as P = 1.98 × 10-4 (0.05/252). Conditional logistic regression revealed the most significant interaction between rs2330542 in FGF10 and rs1946295 in TBX5, which remained significant (P = 9.63 × 10-6 ) after Bonferroni correction. The relative risk of allele C in rs2330542 (FGF10) was 1.02 (95%CI 0.81-1.28), while the relative risk was 1.42 (95%CI 1.03-1.97) when the exposure was a combination of allele C in rs2330542 and allele A in rs1946295 (TBX5). Our findings confirmed the importance of considering G × G interaction when exploring the genetic risk factors of NSCL/P. Further investigations are warranted to validate the potential interaction and reveal the biological function of FGF10/FGFR2/TBX5. Environ. Mol. Mutagen. 2019. © 2019 Wiley Periodicals, Inc.

11.
Nat Genet ; 51(3): 481-493, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30804560

RESUMO

Reduced lung function predicts mortality and is key to the diagnosis of chronic obstructive pulmonary disease (COPD). In a genome-wide association study in 400,102 individuals of European ancestry, we define 279 lung function signals, 139 of which are new. In combination, these variants strongly predict COPD in independent populations. Furthermore, the combined effect of these variants showed generalizability across smokers and never smokers, and across ancestral groups. We highlight biological pathways, known and potential drug targets for COPD and, in phenome-wide association studies, autoimmune-related and other pleiotropic effects of lung function-associated variants. This new genetic evidence has potential to improve future preventive and therapeutic strategies for COPD.


Assuntos
Predisposição Genética para Doença/genética , Pulmão/fisiopatologia , Doença Pulmonar Obstrutiva Crônica/genética , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Feminino , Estudo de Associação Genômica Ampla/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único/genética , Fatores de Risco , Fumar/genética
12.
Nat Genet ; 51(3): 494-505, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30804561

RESUMO

Chronic obstructive pulmonary disease (COPD) is the leading cause of respiratory mortality worldwide. Genetic risk loci provide new insights into disease pathogenesis. We performed a genome-wide association study in 35,735 cases and 222,076 controls from the UK Biobank and additional studies from the International COPD Genetics Consortium. We identified 82 loci associated with P < 5 × 10-8; 47 of these were previously described in association with either COPD or population-based measures of lung function. Of the remaining 35 new loci, 13 were associated with lung function in 79,055 individuals from the SpiroMeta consortium. Using gene expression and regulation data, we identified functional enrichment of COPD risk loci in lung tissue, smooth muscle, and several lung cell types. We found 14 COPD loci shared with either asthma or pulmonary fibrosis. COPD genetic risk loci clustered into groups based on associations with quantitative imaging features and comorbidities. Our analyses provide further support for the genetic susceptibility and heterogeneity of COPD.


Assuntos
Predisposição Genética para Doença/genética , Doença Pulmonar Obstrutiva Crônica/genética , Adulto , Idoso , Asma/genética , Estudos de Casos e Controles , Feminino , Expressão Gênica/genética , Loci Gênicos/genética , Estudo de Associação Genômica Ampla/métodos , Humanos , Pulmão/fisiopatologia , Masculino , Pessoa de Meia-Idade , Fenótipo , Polimorfismo de Nucleotídeo Único/genética , Fibrose Pulmonar/genética , Fumar/genética
13.
Artigo em Inglês | MEDLINE | ID: mdl-30769929

RESUMO

Non-syndromic cleft lip with or without cleft palate (NSCL/P) is one of common birth defects in China, with genetic and environmental components contributing to the etiology. Genome wide association studies (GWASs) have identified SPRY1 and SPRY2 to be associated with NSCL/P among Chinese populations. This study aimed to further explore potential genetic effect and gene-environment interaction among SPRY genes based on haplotype analysis, using 806 Chinese case-parent NSCL/P trios drawn from an international consortium which conducted a genome-wide association study. After the process of quality control, 190 single nucleotide polymorphisms (SNPs) of SPRY genes were included for analyses. Haplotype and haplotype-environment interaction analyses were conducted in Population-Based Association Test (PBAT) software. A 2-SNP haplotype and three 3-SNP haplotypes showed a significant association with the risk of NSCL/P after Bonferroni correction (corrected significance level = 2.6 × 10-4). Moreover, haplotype-environment interaction analysis identified these haplotypes respectively showing statistically significant interactions with maternal multivitamin supplementation or maternal environmental tobacco smoke. This study showed SPRY2 to be associated with NSCL/P among the Chinese population through not only gene effects, but also a gene-environment interaction, highlighting the importance of considering environmental exposures in the genetic etiological study of NSCL/P.


Assuntos
Fenda Labial/genética , Fissura Palatina/genética , Peptídeos e Proteínas de Sinalização Intracelular/genética , Proteínas de Membrana/genética , Grupo com Ancestrais do Continente Asiático/genética , China , Suplementos Nutricionais , Feminino , Interação Gene-Ambiente , Estudo de Associação Genômica Ampla , Haplótipos , Humanos , Masculino , Mães , Polimorfismo de Nucleotídeo Único , Poluição por Fumaça de Tabaco , Vitaminas/administração & dosagem
14.
Genet Epidemiol ; 43(3): 318-329, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30740764

RESUMO

Genetic association studies have increasingly recognized variant effects on multiple phenotypes. Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease with environmental and genetic causes. Multiple genetic variants have been associated with COPD, many of which show significant associations to additional phenotypes. However, it is unknown if these associations represent biological pleiotropy or if they exist through correlation of related phenotypes ("mediated pleiotropy"). Using 6,670 subjects from the COPDGene study, we describe the association of known COPD susceptibility loci with other COPD-related phenotypes and distinguish if these act directly on the phenotypes (i.e., biological pleiotropy) or if the association is due to correlation (i.e., mediated pleiotropy). We identified additional associated phenotypes for 13 of 25 known COPD loci. Tests for pleiotropy between genotype and associated outcomes were significant for all loci. In cases of significant pleiotropy, we performed mediation analysis to test if SNPs had a direct association to phenotype. Most loci showed a mediated effect through the hypothesized causal pathway. However, many loci also had direct associations, suggesting causal explanations (i.e., emphysema leading to reduced lung function) are incomplete. Our results highlight the high degree of pleiotropy in complex disease-associated loci and provide novel insights into the mechanisms underlying COPD.


Assuntos
Loci Gênicos , Pleiotropia Genética , Predisposição Genética para Doença , Doença Pulmonar Obstrutiva Crônica/genética , Idoso , Idoso de 80 Anos ou mais , Feminino , Estudo de Associação Genômica Ampla , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Fenótipo , Polimorfismo de Nucleotídeo Único/genética
16.
Nat Genet ; 2018 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-30455414

RESUMO

We used a deeply sequenced dataset of 910 individuals, all of African descent, to construct a set of DNA sequences that is present in these individuals but missing from the reference human genome. We aligned 1.19 trillion reads from the 910 individuals to the reference genome (GRCh38), collected all reads that failed to align, and assembled these reads into contiguous sequences (contigs). We then compared all contigs to one another to identify a set of unique sequences representing regions of the African pan-genome missing from the reference genome. Our analysis revealed 296,485,284 bp in 125,715 distinct contigs present in the populations of African descent, demonstrating that the African pan-genome contains ~10% more DNA than the current human reference genome. Although the functional significance of nearly all of this sequence is unknown, 387 of the novel contigs fall within 315 distinct protein-coding genes, and the rest appear to be intergenic.

17.
J Mol Med (Berl) ; 96(12): 1375-1385, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30353303

RESUMO

Chronic obstructive pulmonary disease (COPD) is a leading cause of death worldwide, and long-term oxygen therapy has been shown to reduce mortality in COPD patients with severe hypoxemia. However, the Long-term Oxygen Treatment Trial (LOTT), a large randomized trial, found no benefit of oxygen therapy in COPD patients with moderate hypoxemia. We hypothesized that there may be differences in response to oxygen which depend on genotype or gene expression. In a genome-wide time-to-event analysis of the primary outcome of death or hospitalization in 331 subjects, 97 single nucleotide polymorphisms (SNPs) showed evidence of interaction with oxygen therapy at P < 1e-5, including 7 SNPs near arylsulfatase B (ARSB; P = 6e-6). In microarray expression profiling on 51 whole blood samples from 37 individuals, at screening and/or at 12-month follow-up, ARSB expression was associated with the primary outcome depending on oxygen treatment. The significant SNPs were conditional expression quantitative trait loci for ARSB expression. In a network analysis of genes affected by long-term oxygen, two observed clusters including 26 co-expressed genes were enriched in mitochondrial function. Using data from the observational COPDGene Study, we validated the expression of 25 of these 26 genes, plus ARSB. The effect of long-term oxygen therapy in COPD varied based on ARSB expression and genotype. ARSB has previously been shown to be associated with hypoxemia in human bronchial and colonic epithelial cells and in a mouse model. In peripheral blood, long-term oxygen treatment affected expression of mitochondrial-related genes, a biologically relevant pathway in COPD. SNPs and expression of ARSB are associated with response to long-term oxygen in COPD. The ARSB SNPs were expression quantitative trait loci depending on oxygen therapy. Genes differentially expressed by long-term oxygen were enriched in mitochondrial functions. This suggests a potential biomarker to personalize use of long-term oxygen in COPD.

18.
Respir Res ; 19(1): 209, 2018 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-30373671

RESUMO

BACKGROUND: Childhood asthma is strongly influenced by genetics and is a risk factor for reduced lung function and chronic obstructive pulmonary disease (COPD) in adults. This study investigates self-reported childhood asthma in adult smokers from the COPDGene Study. We hypothesize that childhood asthma is associated with decreased lung function, increased risk for COPD, and that a genome-wide association study (GWAS) will show association with established asthma variants. METHODS: We evaluated current and former smokers ages 45-80 of non-Hispanic white (NHW) or African American (AA) race. Childhood asthma was defined by self-report of asthma, diagnosed by a medical professional, with onset at < 16 years or during childhood. Subjects with a history of childhood asthma were compared to those who never had asthma based on lung function, development of COPD, and genetic variation. GWAS was performed in NHW and AA populations, and combined in meta-analysis. Two sets of established asthma SNPs from published literature were examined for association with childhood asthma. RESULTS: Among 10,199 adult smokers, 730 (7%) reported childhood asthma and 7493 (73%) reported no history of asthma. Childhood asthmatics had reduced lung function and increased risk for COPD (OR 3.42, 95% CI 2.81-4.18). Genotype data was assessed for 8031 subjects. Among NHWs, 391(7%) had childhood asthma, and GWAS identified one genome-wide significant association in KIAA1958 (rs59289606, p = 4.82 × 10- 8). Among AAs, 339 (12%) had childhood asthma. No SNPs reached genome-wide significance in the AAs or in the meta-analysis combining NHW and AA subjects; however, potential regions of interest were identified. Established asthma SNPs were examined, seven from the NHGRI-EBI database and five with genome-wide significance in the largest pediatric asthma GWAS. Associations were found in the current childhood asthma GWAS with known asthma loci in IL1RL1, IL13, LINC01149, near GSDMB, and in the C11orf30-LRRC32 region (Bonferroni adjusted p < 0.05 for all comparisons). CONCLUSIONS: Childhood asthmatics are at increased risk for COPD. Defining asthma by self-report is valid in populations at risk for COPD, identifying subjects with clinical and genetic characteristics known to associate with childhood asthma. This has potential to improve clinical understanding of asthma-COPD overlap (ACO) and enhance future research into ACO-specific treatment regimens. TRIAL REGISTRATION: ClinicalTrials.gov, NCT00608764 (Active since January 28, 2008).

19.
Genet Epidemiol ; 2018 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-30246882

RESUMO

We previously demonstrated how sharing of rare variants (RVs) in distant affected relatives can be used to identify variants causing a complex and heterogeneous disease. This approach tested whether single RVs were shared by all sequenced affected family members. However, as with other study designs, joint analysis of several RVs (e.g., within genes) is sometimes required to obtain sufficient statistical power. Further, phenocopies can lead to false negatives for some causal RVs if complete sharing among affected is required. Here, we extend our methodology (Rare Variant Sharing, RVS) to address these issues. Specifically, we introduce gene-based analyses, a partial sharing test based on RV sharing probabilities for subsets of affected relatives and a haplotype-based RV definition. RVS also has the desirable feature of not requiring external estimates of variant frequency or control samples, provides functionality to assess and address violations of key assumptions, and is available as open source software for genome-wide analysis. Simulations including phenocopies, based on the families of an oral cleft study, revealed the partial and complete sharing versions of RVS achieved similar statistical power compared with alternative methods (RareIBD and the Gene-Based Segregation Test), and had superior power compared with the pedigree Variant Annotation, Analysis, and Search Tool (pVAAST) linkage statistic. In studies of multiplex cleft families, analysis of rare single nucleotide variants in the exome of 151 affected relatives from 54 families revealed no significant excess sharing in any one gene, but highlighted different patterns of sharing revealed by the complete and partial sharing tests.

20.
Sci Rep ; 8(1): 14439, 2018 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-30262855

RESUMO

The polygenic nature of complex diseases offers potential opportunities to utilize network-based approaches that leverage the comprehensive set of protein-protein interactions (the human interactome) to identify new genes of interest and relevant biological pathways. However, the incompleteness of the current human interactome prevents it from reaching its full potential to extract network-based knowledge from gene discovery efforts, such as genome-wide association studies, for complex diseases like chronic obstructive pulmonary disease (COPD). Here, we provide a framework that integrates the existing human interactome information with experimental protein-protein interaction data for FAM13A, one of the most highly associated genetic loci to COPD, to find a more comprehensive disease network module. We identified an initial disease network neighborhood by applying a random-walk method. Next, we developed a network-based closeness approach (CAB) that revealed 9 out of 96 FAM13A interacting partners identified by affinity purification assays were significantly close to the initial network neighborhood. Moreover, compared to a similar method (local radiality), the CAB approach predicts low-degree genes as potential candidates. The candidates identified by the network-based closeness approach were combined with the initial network neighborhood to build a comprehensive disease network module (163 genes) that was enriched with genes differentially expressed between controls and COPD subjects in alveolar macrophages, lung tissue, sputum, blood, and bronchial brushing datasets. Overall, we demonstrate an approach to find disease-related network components using new laboratory data to overcome incompleteness of the current interactome.

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