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1.
medRxiv ; 2023 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-37333246

RESUMEN

Polygenic risk scores (PRS) have improved in predictive performance supporting their use in clinical practice. Reduced predictive performance of PRS in diverse populations can exacerbate existing health disparities. The NHGRI-funded eMERGE Network is returning a PRS-based genome-informed risk assessment to 25,000 diverse adults and children. We assessed PRS performance, medical actionability, and potential clinical utility for 23 conditions. Standardized metrics were considered in the selection process with additional consideration given to strength of evidence in African and Hispanic populations. Ten conditions were selected with a range of high-risk thresholds: atrial fibrillation, breast cancer, chronic kidney disease, coronary heart disease, hypercholesterolemia, prostate cancer, asthma, type 1 diabetes, obesity, and type 2 diabetes. We developed a pipeline for clinical PRS implementation, used genetic ancestry to calibrate PRS mean and variance, created a framework for regulatory compliance, and developed a PRS clinical report. eMERGE's experience informs the infrastructure needed to implement PRS-based implementation in diverse clinical settings.

2.
Genet Med ; 25(4): 100006, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36621880

RESUMEN

PURPOSE: Assessing the risk of common, complex diseases requires consideration of clinical risk factors as well as monogenic and polygenic risks, which in turn may be reflected in family history. Returning risks to individuals and providers may influence preventive care or use of prophylactic therapies for those individuals at high genetic risk. METHODS: To enable integrated genetic risk assessment, the eMERGE (electronic MEdical Records and GEnomics) network is enrolling 25,000 diverse individuals in a prospective cohort study across 10 sites. The network developed methods to return cross-ancestry polygenic risk scores, monogenic risks, family history, and clinical risk assessments via a genome-informed risk assessment (GIRA) report and will assess uptake of care recommendations after return of results. RESULTS: GIRAs include summary care recommendations for 11 conditions, education pages, and clinical laboratory reports. The return of high-risk GIRA to individuals and providers includes guidelines for care and lifestyle recommendations. Assembling the GIRA required infrastructure and workflows for ingesting and presenting content from multiple sources. Recruitment began in February 2022. CONCLUSION: Return of a novel report for communicating monogenic, polygenic, and family history-based risk factors will inform the benefits of integrated genetic risk assessment for routine health care.


Asunto(s)
Genoma , Genómica , Humanos , Estudios Prospectivos , Genómica/métodos , Factores de Riesgo , Medición de Riesgo
3.
Elife ; 4: e00662, 2015 Feb 03.
Artículo en Inglés | MEDLINE | ID: mdl-25646566

RESUMEN

Candida albicans is both a member of the healthy human microbiome and a major pathogen in immunocompromised individuals. Infections are typically treated with azole inhibitors of ergosterol biosynthesis often leading to drug resistance. Studies in clinical isolates have implicated multiple mechanisms in resistance, but have focused on large-scale aberrations or candidate genes, and do not comprehensively chart the genetic basis of adaptation. Here, we leveraged next-generation sequencing to analyze 43 isolates from 11 oral candidiasis patients. We detected newly selected mutations, including single-nucleotide polymorphisms (SNPs), copy-number variations and loss-of-heterozygosity (LOH) events. LOH events were commonly associated with acquired resistance, and SNPs in 240 genes may be related to host adaptation. Conversely, most aneuploidies were transient and did not correlate with drug resistance. Our analysis also shows that isolates also varied in adherence, filamentation, and virulence. Our work reveals new molecular mechanisms underlying the evolution of drug resistance and host adaptation.


Asunto(s)
Candida albicans/efectos de los fármacos , Candida albicans/genética , Candidiasis/microbiología , Farmacorresistencia Fúngica/efectos de los fármacos , Farmacorresistencia Fúngica/genética , Evolución Molecular , Adhesividad , Aneuploidia , Candida albicans/aislamiento & purificación , Fluconazol/farmacología , Aptitud Genética/efectos de los fármacos , Genoma Humano , Interacciones Huésped-Patógeno/efectos de los fármacos , Interacciones Huésped-Patógeno/genética , Humanos , Pérdida de Heterocigocidad/genética , Pruebas de Sensibilidad Microbiana , Mutación/genética , Fenotipo , Polimorfismo de Nucleótido Simple/genética , Análisis de Secuencia de ADN , Virulencia/efectos de los fármacos , Virulencia/genética
4.
J Clin Endocrinol Metab ; 99(5): E926-30, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24471563

RESUMEN

CONTEXT/OBJECTIVE: The variant rs13266634 in SLC30A8, encoding a ß-cell-specific zinc transporter, is associated with type 2 diabetes. We aimed to identify other variants in SLC30A8 that increase diabetes risk and impair ß-cell function, and test whether zinc intake modifies this risk. DESIGN/OUTCOME: We sequenced exons in SLC30A8 in 380 Diabetes Prevention Program (DPP) participants and identified 44 novel variants, which were genotyped in 3445 DPP participants and tested for association with diabetes incidence and measures of insulin secretion and processing. We examined individual common variants and used gene burden tests to test 39 rare variants in aggregate. RESULTS: We detected a near-nominal association between a rare-variant genotype risk score and diabetes risk. Five common variants were associated with the oral disposition index. Various methods aggregating rare variants demonstrated associations with changes in oral disposition index and insulinogenic index during year 1 of follow-up. We did not find a clear interaction of zinc intake with genotype on diabetes incidence. CONCLUSIONS: Individual common and an aggregate of rare genetic variation in SLC30A8 are associated with measures of ß-cell function in the DPP. Exploring rare variation may complement ongoing efforts to uncover the genetic influences that underlie complex diseases.


Asunto(s)
Proteínas de Transporte de Catión/genética , Diabetes Mellitus Tipo 2/genética , Células Secretoras de Insulina/metabolismo , Polimorfismo de Nucleótido Simple , Adulto , Alelos , Diabetes Mellitus Tipo 2/epidemiología , Diabetes Mellitus Tipo 2/metabolismo , Femenino , Frecuencia de los Genes , Estudios de Asociación Genética , Predisposición Genética a la Enfermedad , Humanos , Incidencia , Insulina/metabolismo , Secreción de Insulina , Masculino , Persona de Mediana Edad , Transportador 8 de Zinc
5.
Cell ; 153(3): 666-77, 2013 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-23622249

RESUMEN

The analysis of exonic DNA from prostate cancers has identified recurrently mutated genes, but the spectrum of genome-wide alterations has not been profiled extensively in this disease. We sequenced the genomes of 57 prostate tumors and matched normal tissues to characterize somatic alterations and to study how they accumulate during oncogenesis and progression. By modeling the genesis of genomic rearrangements, we identified abundant DNA translocations and deletions that arise in a highly interdependent manner. This phenomenon, which we term "chromoplexy," frequently accounts for the dysregulation of prostate cancer genes and appears to disrupt multiple cancer genes coordinately. Our modeling suggests that chromoplexy may induce considerable genomic derangement over relatively few events in prostate cancer and other neoplasms, supporting a model of punctuated cancer evolution. By characterizing the clonal hierarchy of genomic lesions in prostate tumors, we charted a path of oncogenic events along which chromoplexy may drive prostate carcinogenesis.


Asunto(s)
Aberraciones Cromosómicas , Regulación Neoplásica de la Expresión Génica , Genoma Humano , Neoplasias de la Próstata/genética , Adenocarcinoma/genética , Adenocarcinoma/patología , Estudios de Cohortes , Estudio de Asociación del Genoma Completo , Humanos , Masculino , Tumores Neuroendocrinos/genética , Tumores Neuroendocrinos/patología , Neoplasias de la Próstata/patología
6.
Nat Genet ; 45(5): 478-86, 2013 May.
Artículo en Inglés | MEDLINE | ID: mdl-23525077

RESUMEN

The incidence of esophageal adenocarcinoma (EAC) has risen 600% over the last 30 years. With a 5-year survival rate of ~15%, the identification of new therapeutic targets for EAC is greatly important. We analyze the mutation spectra from whole-exome sequencing of 149 EAC tumor-normal pairs, 15 of which have also been subjected to whole-genome sequencing. We identify a mutational signature defined by a high prevalence of A>C transversions at AA dinucleotides. Statistical analysis of exome data identified 26 significantly mutated genes. Of these genes, five (TP53, CDKN2A, SMAD4, ARID1A and PIK3CA) have previously been implicated in EAC. The new significantly mutated genes include chromatin-modifying factors and candidate contributors SPG20, TLR4, ELMO1 and DOCK2. Functional analyses of EAC-derived mutations in ELMO1 identifies increased cellular invasion. Therefore, we suggest the potential activation of the RAC1 pathway as a contributor to EAC tumorigenesis.


Asunto(s)
Adenocarcinoma/genética , Biomarcadores de Tumor/genética , Neoplasias Esofágicas/genética , Exoma/genética , Genoma Humano/genética , Mutación/genética , Mapeo Cromosómico , Reordenamiento Génico , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Invasividad Neoplásica
7.
Diabetes Care ; 36(1): 13-9, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-22933432

RESUMEN

OBJECTIVE: To examine whether diabetes genetic risk testing and counseling can improve diabetes prevention behaviors. RESEARCH DESIGN AND METHODS: We conducted a randomized trial of diabetes genetic risk counseling among overweight patients at increased phenotypic risk for type 2 diabetes. Participants were randomly allocated to genetic testing versus no testing. Genetic risk was calculated by summing 36 single nucleotide polymorphisms associated with type 2 diabetes. Participants in the top and bottom score quartiles received individual genetic counseling before being enrolled with untested control participants in a 12-week, validated, diabetes prevention program. Middle-risk quartile participants were not studied further. We examined the effect of this genetic counseling intervention on patient self-reported attitudes, program attendance, and weight loss, separately comparing higher-risk and lower-risk result recipients with control participants. RESULTS: The 108 participants enrolled in the diabetes prevention program included 42 participants at higher diabetes genetic risk, 32 at lower diabetes genetic risk, and 34 untested control subjects. Mean age was 57.9 ± 10.6 years, 61% were men, and average BMI was 34.8 kg/m(2), with no differences among randomization groups. Participants attended 6.8 ± 4.3 group sessions and lost 8.5 ± 10.1 pounds, with 33 of 108 (30.6%) losing ≥5% body weight. There were few statistically significant differences in self-reported motivation, program attendance, or mean weight loss when higher-risk recipients and lower-risk recipients were compared with control subjects (P > 0.05 for all but one comparison). CONCLUSIONS: Diabetes genetic risk counseling with currently available variants does not significantly alter self-reported motivation or prevention program adherence for overweight individuals at risk for diabetes.


Asunto(s)
Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/prevención & control , Asesoramiento Genético , Anciano , Femenino , Pruebas Genéticas , Humanos , Masculino , Persona de Mediana Edad , Motivación , Sobrepeso
8.
Am J Hum Genet ; 92(1): 15-27, 2013 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-23261300

RESUMEN

The extent to which variants in the protein-coding sequence of genes contribute to risk of rheumatoid arthritis (RA) is unknown. In this study, we addressed this issue by deep exon sequencing and large-scale genotyping of 25 biological candidate genes located within RA risk loci discovered by genome-wide association studies (GWASs). First, we assessed the contribution of rare coding variants in the 25 genes to the risk of RA in a pooled sequencing study of 500 RA cases and 650 controls of European ancestry. We observed an accumulation of rare nonsynonymous variants exclusive to RA cases in IL2RA and IL2RB (burden test: p = 0.007 and p = 0.018, respectively). Next, we assessed the aggregate contribution of low-frequency and common coding variants to the risk of RA by dense genotyping of the 25 gene loci in 10,609 RA cases and 35,605 controls. We observed a strong enrichment of coding variants with a nominal signal of association with RA (p < 0.05) after adjusting for the best signal of association at the loci (p(enrichment) = 6.4 × 10(-4)). For one locus containing CD2, we found that a missense variant, rs699738 (c.798C>A [p.His266Gln]), and a noncoding variant, rs624988, reside on distinct haplotypes and independently contribute to the risk of RA (p = 4.6 × 10(-6)). Overall, our results indicate that variants (distributed across the allele-frequency spectrum) within the protein-coding portion of a subset of biological candidate genes identified by GWASs contribute to the risk of RA. Further, we have demonstrated that very large sample sizes will be required for comprehensively identifying the independent alleles contributing to the missing heritability of RA.


Asunto(s)
Artritis Reumatoide/genética , Frecuencia de los Genes , Predisposición Genética a la Enfermedad , Variación Genética , Polimorfismo de Nucleótido Simple , Exones , Estudio de Asociación del Genoma Completo , Humanos , Factores de Riesgo
9.
PLoS Genet ; 8(9): e1002921, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23028342

RESUMEN

Diabetic kidney disease, or diabetic nephropathy (DN), is a major complication of diabetes and the leading cause of end-stage renal disease (ESRD) that requires dialysis treatment or kidney transplantation. In addition to the decrease in the quality of life, DN accounts for a large proportion of the excess mortality associated with type 1 diabetes (T1D). Whereas the degree of glycemia plays a pivotal role in DN, a subset of individuals with poorly controlled T1D do not develop DN. Furthermore, strong familial aggregation supports genetic susceptibility to DN. However, the genes and the molecular mechanisms behind the disease remain poorly understood, and current therapeutic strategies rarely result in reversal of DN. In the GEnetics of Nephropathy: an International Effort (GENIE) consortium, we have undertaken a meta-analysis of genome-wide association studies (GWAS) of T1D DN comprising ~2.4 million single nucleotide polymorphisms (SNPs) imputed in 6,691 individuals. After additional genotyping of 41 top ranked SNPs representing 24 independent signals in 5,873 individuals, combined meta-analysis revealed association of two SNPs with ESRD: rs7583877 in the AFF3 gene (P = 1.2 × 10(-8)) and an intergenic SNP on chromosome 15q26 between the genes RGMA and MCTP2, rs12437854 (P = 2.0 × 10(-9)). Functional data suggest that AFF3 influences renal tubule fibrosis via the transforming growth factor-beta (TGF-ß1) pathway. The strongest association with DN as a primary phenotype was seen for an intronic SNP in the ERBB4 gene (rs7588550, P = 2.1 × 10(-7)), a gene with type 2 diabetes DN differential expression and in the same intron as a variant with cis-eQTL expression of ERBB4. All these detected associations represent new signals in the pathogenesis of DN.


Asunto(s)
Diabetes Mellitus Tipo 1/genética , Nefropatías Diabéticas/genética , Receptores ErbB/genética , Fallo Renal Crónico , Proteínas Nucleares/genética , Diabetes Mellitus Tipo 1/complicaciones , Nefropatías Diabéticas/etiología , Nefropatías Diabéticas/patología , Fibrosis/genética , Fibrosis/metabolismo , Predisposición Genética a la Enfermedad , Estudio de Asociación del Genoma Completo , Humanos , Fallo Renal Crónico/etiología , Fallo Renal Crónico/genética , Fallo Renal Crónico/patología , Túbulos Renales/metabolismo , Túbulos Renales/patología , Polimorfismo de Nucleótido Simple , Sitios de Carácter Cuantitativo/genética , Receptor ErbB-4 , Factor de Crecimiento Transformador beta1/genética , Factor de Crecimiento Transformador beta1/metabolismo
10.
Diabetes ; 61(8): 2187-94, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22721967

RESUMEN

We formed the GEnetics of Nephropathy-an International Effort (GENIE) consortium to examine previously reported genetic associations with diabetic nephropathy (DN) in type 1 diabetes. GENIE consists of 6,366 similarly ascertained participants of European ancestry with type 1 diabetes, with and without DN, from the All Ireland-Warren 3-Genetics of Kidneys in Diabetes U.K. and Republic of Ireland (U.K.-R.O.I.) collection and the Finnish Diabetic Nephropathy Study (FinnDiane), combined with reanalyzed data from the Genetics of Kidneys in Diabetes U.S. Study (U.S. GoKinD). We found little evidence for the association of the EPO promoter polymorphism, rs161740, with the combined phenotype of proliferative retinopathy and end-stage renal disease in U.K.-R.O.I. (odds ratio [OR] 1.14, P = 0.19) or FinnDiane (OR 1.06, P = 0.60). However, a fixed-effects meta-analysis that included the previously reported cohorts retained a genome-wide significant association with that phenotype (OR 1.31, P = 2 × 10(-9)). An expanded investigation of the ELMO1 locus and genetic regions reported to be associated with DN in the U.S. GoKinD yielded only nominal statistical significance for these loci. Finally, top candidates identified in a recent meta-analysis failed to reach genome-wide significance. In conclusion, we were unable to replicate most of the previously reported genetic associations for DN, and significance for the EPO promoter association was attenuated.


Asunto(s)
Diabetes Mellitus Tipo 1/epidemiología , Nefropatías Diabéticas/genética , Proteínas Adaptadoras Transductoras de Señales/genética , Adulto , Estudios de Casos y Controles , Diabetes Mellitus Tipo 1/genética , Nefropatías Diabéticas/epidemiología , Eritropoyetina/genética , Finlandia/epidemiología , Predisposición Genética a la Enfermedad , Estudio de Asociación del Genoma Completo , Humanos , Irlanda/epidemiología , Fallo Renal Crónico/genética , Fenotipo , Regiones Promotoras Genéticas/genética , Estados Unidos/epidemiología , Población Blanca/genética
11.
Nat Genet ; 44(6): 685-9, 2012 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-22610119

RESUMEN

Prostate cancer is the second most common cancer in men worldwide and causes over 250,000 deaths each year. Overtreatment of indolent disease also results in significant morbidity. Common genetic alterations in prostate cancer include losses of NKX3.1 (8p21) and PTEN (10q23), gains of AR (the androgen receptor gene) and fusion of ETS family transcription factor genes with androgen-responsive promoters. Recurrent somatic base-pair substitutions are believed to be less contributory in prostate tumorigenesis but have not been systematically analyzed in large cohorts. Here, we sequenced the exomes of 112 prostate tumor and normal tissue pairs. New recurrent mutations were identified in multiple genes, including MED12 and FOXA1. SPOP was the most frequently mutated gene, with mutations involving the SPOP substrate-binding cleft in 6-15% of tumors across multiple independent cohorts. Prostate cancers with mutant SPOP lacked ETS family gene rearrangements and showed a distinct pattern of genomic alterations. Thus, SPOP mutations may define a new molecular subtype of prostate cancer.


Asunto(s)
Factor Nuclear 3-alfa del Hepatocito/genética , Complejo Mediador/genética , Proteínas Asociadas a Microtúbulos/genética , Mutación , Neoplasias de la Próstata/genética , Exoma , Humanos , Masculino , Análisis de Secuencia de ADN
12.
Nat Genet ; 43(8): 801-5, 2011 Jul 24.
Artículo en Inglés | MEDLINE | ID: mdl-21775993

RESUMEN

Noncoding variants at human chromosome 9p21 near CDKN2A and CDKN2B are associated with type 2 diabetes, myocardial infarction, aneurysm, vertical cup disc ratio and at least five cancers. Here we compare approaches to more comprehensively assess genetic variation in the region. We carried out targeted sequencing at high coverage in 47 individuals and compared the results to pilot data from the 1000 Genomes Project. We imputed variants into type 2 diabetes and myocardial infarction cohorts directly from targeted sequencing, from a genotyped reference panel derived from sequencing and from 1000 Genomes Project low-coverage data. Polymorphisms with frequency >5% were captured well by all strategies. Imputation of intermediate-frequency polymorphisms required a higher density of tag SNPs in disease samples than is available on first-generation genome-wide association study (GWAS) arrays. Our association analyses identified more comprehensive sets of variants showing equivalent statistical association with type 2 diabetes or myocardial infarction, but did not identify stronger associations than the original GWAS signals.


Asunto(s)
Mapeo Cromosómico , Cromosomas Humanos Par 9/genética , Diabetes Mellitus Tipo 2/genética , Variación Genética/genética , Estudio de Asociación del Genoma Completo , Infarto del Miocardio/genética , Polimorfismo de Nucleótido Simple/genética , Genoma Humano , Haplotipos/genética , Humanos
13.
Science ; 333(6046): 1157-60, 2011 Aug 26.
Artículo en Inglés | MEDLINE | ID: mdl-21798893

RESUMEN

Head and neck squamous cell carcinoma (HNSCC) is a common, morbid, and frequently lethal malignancy. To uncover its mutational spectrum, we analyzed whole-exome sequencing data from 74 tumor-normal pairs. The majority exhibited a mutational profile consistent with tobacco exposure; human papillomavirus was detectable by sequencing DNA from infected tumors. In addition to identifying previously known HNSCC genes (TP53, CDKN2A, PTEN, PIK3CA, and HRAS), our analysis revealed many genes not previously implicated in this malignancy. At least 30% of cases harbored mutations in genes that regulate squamous differentiation (for example, NOTCH1, IRF6, and TP63), implicating its dysregulation as a major driver of HNSCC carcinogenesis. More generally, the results indicate the ability of large-scale sequencing to reveal fundamental tumorigenic mechanisms.


Asunto(s)
Carcinoma/genética , Neoplasias de Cabeza y Cuello/genética , Mutación , Neoplasias de Células Escamosas/genética , Receptor Notch1/genética , Análisis de Secuencia de ADN , Algoritmos , Apoptosis , Carcinoma/metabolismo , Carcinoma/virología , Carcinoma de Células Escamosas , Diferenciación Celular , Exones , Neoplasias de Cabeza y Cuello/metabolismo , Neoplasias de Cabeza y Cuello/virología , Humanos , Neoplasias de Células Escamosas/metabolismo , Neoplasias de Células Escamosas/virología , Papillomaviridae/aislamiento & purificación , Infecciones por Papillomavirus/virología , Mutación Puntual , Receptor Notch1/metabolismo , Eliminación de Secuencia , Transducción de Señal , Fumar , Carcinoma de Células Escamosas de Cabeza y Cuello , Nicotiana
14.
Nat Genet ; 43(8): 753-60, 2011 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-21706003

RESUMEN

Genome-wide association studies have identified 32 loci influencing body mass index, but this measure does not distinguish lean from fat mass. To identify adiposity loci, we meta-analyzed associations between ∼2.5 million SNPs and body fat percentage from 36,626 individuals and followed up the 14 most significant (P < 10(-6)) independent loci in 39,576 individuals. We confirmed a previously established adiposity locus in FTO (P = 3 × 10(-26)) and identified two new loci associated with body fat percentage, one near IRS1 (P = 4 × 10(-11)) and one near SPRY2 (P = 3 × 10(-8)). Both loci contain genes with potential links to adipocyte physiology. Notably, the body-fat-decreasing allele near IRS1 is associated with decreased IRS1 expression and with an impaired metabolic profile, including an increased visceral to subcutaneous fat ratio, insulin resistance, dyslipidemia, risk of diabetes and coronary artery disease and decreased adiponectin levels. Our findings provide new insights into adiposity and insulin resistance.


Asunto(s)
Adiposidad/genética , Variación Genética/genética , Proteínas Sustrato del Receptor de Insulina/genética , Metaboloma/genética , Obesidad/genética , Polimorfismo de Nucleótido Simple/genética , Adiponectina/sangre , Alelos , Distribución de la Grasa Corporal , Índice de Masa Corporal , Peso Corporal , Femenino , Estudio de Asociación del Genoma Completo , Humanos , Péptidos y Proteínas de Señalización Intracelular/genética , Masculino , Proteínas de la Membrana , Metaanálisis como Asunto , Grasa Subcutánea
15.
Hum Genet ; 130(5): 685-99, 2011 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-21597964

RESUMEN

Three founder mutations in BRCA1 and BRCA2 contribute to the risk of hereditary breast and ovarian cancer in Ashkenazi Jews (AJ). They are observed at increased frequency in the AJ compared to other BRCA mutations in Caucasian non-Jews (CNJ). Several authors have proposed that elevated allele frequencies in the surrounding genomic regions reflect adaptive or balancing selection. Such proposals predict long-range linkage disequilibrium (LD) resulting from a selective sweep, although genetic drift in a founder population may also act to create long-distance LD. To date, few studies have used the tools of statistical genomics to examine the likelihood of long-range LD at a deleterious locus in a population that faced a genetic bottleneck. We studied the genotypes of hundreds of women from a large international consortium of BRCA1 and BRCA2 mutation carriers and found that AJ women exhibited long-range haplotypes compared to CNJ women. More than 50% of the AJ chromosomes with the BRCA1 185delAG mutation share an identical 2.1 Mb haplotype and nearly 16% of AJ chromosomes carrying the BRCA2 6174delT mutation share a 1.4 Mb haplotype. Simulations based on the best inference of Ashkenazi population demography indicate that long-range haplotypes are expected in the context of a genome-wide survey. Our results are consistent with the hypothesis that a local bottleneck effect from population size constriction events could by chance have resulted in the large haplotype blocks observed at high frequency in the BRCA1 and BRCA2 regions of Ashkenazi Jews.


Asunto(s)
Artritis/genética , Proteína BRCA1/genética , Proteína BRCA2/genética , Sordera/genética , Haplotipos/genética , Policondritis Recurrente/genética , Secuencia de Bases , Simulación por Computador , Femenino , Efecto Fundador , Genotipo , Heterocigoto , Humanos , Judíos/genética , Eliminación de Secuencia
16.
Hum Genet ; 130(5): 607-21, 2011 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-21424828

RESUMEN

Genome-wide genotyping of a cohort using pools rather than individual samples has long been proposed as a cost-saving alternative for performing genome-wide association (GWA) studies. However, successful disease gene mapping using pooled genotyping has thus far been limited to detecting common variants with large effect sizes, which tend not to exist for many complex common diseases or traits. Therefore, for DNA pooling to be a viable strategy for conducting GWA studies, it is important to determine whether commonly used genome-wide SNP array platforms such as the Affymetrix 6.0 array can reliably detect common variants of small effect sizes using pooled DNA. Taking obesity and age at menarche as examples of human complex traits, we assessed the feasibility of genome-wide genotyping of pooled DNA as a single-stage design for phenotype association. By individually genotyping the top associations identified by pooling, we obtained a 14- to 16-fold enrichment of SNPs nominally associated with the phenotype, but we likely missed the top true associations. In addition, we assessed whether genotyping pooled DNA can serve as an inexpensive screen as the second stage of a multi-stage design with a large number of samples by comparing the most cost-effective 3-stage designs with 80% power to detect common variants with genotypic relative risk of 1.1, with and without pooling. Given the current state of the specific technology we employed and the associated genotyping costs, we showed through simulation that a design involving pooling would be 1.07 times more expensive than a design without pooling. Thus, while a significant amount of information exists within the data from pooled DNA, our analysis does not support genotyping pooled DNA as a means to efficiently identify common variants contributing small effects to phenotypes of interest. While our conclusions were based on the specific technology and study design we employed, the approach presented here will be useful for evaluating the utility of other or future genome-wide genotyping platforms in pooled DNA studies.


Asunto(s)
Estudio de Asociación del Genoma Completo/métodos , Análisis de Secuencia por Matrices de Oligonucleótidos/métodos , Análisis de Secuencia de ADN/métodos , Adolescente , Niño , Estudios de Cohortes , Simulación por Computador , Femenino , Variación Genética , Estudio de Asociación del Genoma Completo/economía , Humanos , Masculino , Menarquia/genética , Obesidad/genética , Análisis de Secuencia por Matrices de Oligonucleótidos/economía , Polimorfismo de Nucleótido Simple
17.
PLoS Genet ; 6(10): e1001183, 2010 Oct 28.
Artículo en Inglés | MEDLINE | ID: mdl-21060860

RESUMEN

The considerable uncertainty regarding cancer risks associated with inherited mutations of BRCA2 is due to unknown factors. To investigate whether common genetic variants modify penetrance for BRCA2 mutation carriers, we undertook a two-staged genome-wide association study in BRCA2 mutation carriers. In stage 1 using the Affymetrix 6.0 platform, 592,163 filtered SNPs genotyped were available on 899 young (<40 years) affected and 804 unaffected carriers of European ancestry. Associations were evaluated using a survival-based score test adjusted for familial correlations and stratified by country of the study and BRCA2*6174delT mutation status. The genomic inflation factor (λ) was 1.011. The stage 1 association analysis revealed multiple variants associated with breast cancer risk: 3 SNPs had p-values<10(-5) and 39 SNPs had p-values<10(-4). These variants included several previously associated with sporadic breast cancer risk and two novel loci on chromosome 20 (rs311499) and chromosome 10 (rs16917302). The chromosome 10 locus was in ZNF365, which contains another variant that has recently been associated with breast cancer in an independent study of unselected cases. In stage 2, the top 85 loci from stage 1 were genotyped in 1,264 cases and 1,222 controls. Hazard ratios (HR) and 95% confidence intervals (CI) for stage 1 and 2 were combined and estimated using a retrospective likelihood approach, stratified by country of residence and the most common mutation, BRCA2*6174delT. The combined per allele HR of the minor allele for the novel loci rs16917302 was 0.75 (95% CI 0.66-0.86, ) and for rs311499 was 0.72 (95% CI 0.61-0.85, ). FGFR2 rs2981575 had the strongest association with breast cancer risk (per allele HR = 1.28, 95% CI 1.18-1.39, ). These results indicate that SNPs that modify BRCA2 penetrance identified by an agnostic approach thus far are limited to variants that also modify risk of sporadic BRCA2 wild-type breast cancer.


Asunto(s)
Proteína BRCA2/genética , Neoplasias de la Mama/genética , Estudio de Asociación del Genoma Completo/métodos , Polimorfismo de Nucleótido Simple , Adulto , Cromosomas Humanos Par 10 , Cromosomas Humanos Par 20 , Proteínas de Unión al ADN/genética , Femenino , Frecuencia de los Genes , Predisposición Genética a la Enfermedad/genética , Haplotipos , Heterocigoto , Humanos , Desequilibrio de Ligamiento , Persona de Mediana Edad , Mutación , Penetrancia , Receptor Tipo 2 de Factor de Crecimiento de Fibroblastos/genética , Factores de Riesgo , Factores de Transcripción/genética , Población Blanca/genética
18.
Science ; 330(6010): 1551-7, 2010 Dec 10.
Artículo en Inglés | MEDLINE | ID: mdl-21051598

RESUMEN

Infectious and inflammatory diseases have repeatedly shown strong genetic associations within the major histocompatibility complex (MHC); however, the basis for these associations remains elusive. To define host genetic effects on the outcome of a chronic viral infection, we performed genome-wide association analysis in a multiethnic cohort of HIV-1 controllers and progressors, and we analyzed the effects of individual amino acids within the classical human leukocyte antigen (HLA) proteins. We identified >300 genome-wide significant single-nucleotide polymorphisms (SNPs) within the MHC and none elsewhere. Specific amino acids in the HLA-B peptide binding groove, as well as an independent HLA-C effect, explain the SNP associations and reconcile both protective and risk HLA alleles. These results implicate the nature of the HLA-viral peptide interaction as the major factor modulating durable control of HIV infection.


Asunto(s)
Presentación de Antígeno , Genes MHC Clase I , Infecciones por VIH/genética , Infecciones por VIH/inmunología , VIH-1 , Antígenos HLA-B/genética , Negro o Afroamericano/genética , Alelos , Aminoácidos/fisiología , Linfocitos T CD8-positivos/inmunología , Estudios de Cohortes , Progresión de la Enfermedad , Estudio de Asociación del Genoma Completo , Antígenos VIH/inmunología , Infecciones por VIH/etnología , Infecciones por VIH/virología , Sobrevivientes de VIH a Largo Plazo , VIH-1/inmunología , Antígenos HLA-A/química , Antígenos HLA-A/genética , Antígenos HLA-A/inmunología , Antígenos HLA-A/metabolismo , Antígenos HLA-B/química , Antígenos HLA-B/inmunología , Antígenos HLA-B/metabolismo , Antígenos HLA-C/química , Antígenos HLA-C/genética , Antígenos HLA-C/inmunología , Antígenos HLA-C/metabolismo , Haplotipos , Hispánicos o Latinos/genética , Humanos , Inmunidad Innata , Modelos Logísticos , Modelos Moleculares , Polimorfismo de Nucleótido Simple , Conformación Proteica , Carga Viral , Población Blanca/genética
19.
N Engl J Med ; 363(23): 2220-7, 2010 Dec 02.
Artículo en Inglés | MEDLINE | ID: mdl-20942659

RESUMEN

We sequenced all protein-coding regions of the genome (the "exome") in two family members with combined hypolipidemia, marked by extremely low plasma levels of low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, and triglycerides. These two participants were compound heterozygotes for two distinct nonsense mutations in ANGPTL3 (encoding the angiopoietin-like 3 protein). ANGPTL3 has been reported to inhibit lipoprotein lipase and endothelial lipase, thereby increasing plasma triglyceride and HDL cholesterol levels in rodents. Our finding of ANGPTL3 mutations highlights a role for the gene in LDL cholesterol metabolism in humans and shows the usefulness of exome sequencing for identification of novel genetic causes of inherited disorders. (Funded by the National Human Genome Research Institute and others.).


Asunto(s)
Angiopoyetinas/genética , Codón sin Sentido , Hipobetalipoproteinemias/genética , Proteína 3 Similar a la Angiopoyetina , Proteínas Similares a la Angiopoyetina , HDL-Colesterol/sangre , HDL-Colesterol/genética , LDL-Colesterol/sangre , LDL-Colesterol/genética , Análisis Mutacional de ADN , Femenino , Ligamiento Genético , Humanos , Masculino , Linaje
20.
Lancet ; 376(9750): 1393-400, 2010 Oct 23.
Artículo en Inglés | MEDLINE | ID: mdl-20971364

RESUMEN

BACKGROUND: Comparison of patients with coronary heart disease and controls in genome-wide association studies has revealed several single nucleotide polymorphisms (SNPs) associated with coronary heart disease. We aimed to establish the external validity of these findings and to obtain more precise risk estimates using a prospective cohort design. METHODS: We tested 13 recently discovered SNPs for association with coronary heart disease in a case-control design including participants differing from those in the discovery samples (3829 participants with prevalent coronary heart disease and 48,897 controls free of the disease) and a prospective cohort design including 30,725 participants free of cardiovascular disease from Finland and Sweden. We modelled the 13 SNPs as a multilocus genetic risk score and used Cox proportional hazards models to estimate the association of genetic risk score with incident coronary heart disease. For case-control analyses we analysed associations between individual SNPs and quintiles of genetic risk score using logistic regression. FINDINGS: In prospective cohort analyses, 1264 participants had a first coronary heart disease event during a median 10·7 years' follow-up (IQR 6·7-13·6). Genetic risk score was associated with a first coronary heart disease event. When compared with the bottom quintile of genetic risk score, participants in the top quintile were at 1·66-times increased risk of coronary heart disease in a model adjusting for traditional risk factors (95% CI 1·35-2·04, p value for linear trend=7·3×10(-10)). Adjustment for family history did not change these estimates. Genetic risk score did not improve C index over traditional risk factors and family history (p=0·19), nor did it have a significant effect on net reclassification improvement (2·2%, p=0·18); however, it did have a small effect on integrated discrimination index (0·004, p=0·0006). Results of the case-control analyses were similar to those of the prospective cohort analyses. INTERPRETATION: Using a genetic risk score based on 13 SNPs associated with coronary heart disease, we can identify the 20% of individuals of European ancestry who are at roughly 70% increased risk of a first coronary heart disease event. The potential clinical use of this panel of SNPs remains to be defined. FUNDING: The Wellcome Trust; Academy of Finland Center of Excellence for Complex Disease Genetics; US National Institutes of Health; the Donovan Family Foundation.


Asunto(s)
Enfermedad Coronaria/genética , Estudio de Asociación del Genoma Completo , Polimorfismo de Nucleótido Simple/genética , Adulto , Estudios de Casos y Controles , Femenino , Predisposición Genética a la Enfermedad/genética , Genotipo , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/genética , Modelos de Riesgos Proporcionales , Medición de Riesgo
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