RESUMO
OBJECTIVES: To test the feasibility of randomisation to radical prostatectomy (RP) plus pelvic lymphadenectomy in addition to standard-of-care (SOC) systemic therapy in men with newly diagnosed oligo-metastatic prostate cancer. PATIENTS AND METHODS: A prospective, randomised, non-blinded, feasibility clinical trial with an embedded QuinteT Recruitment Intervention (QRI) to optimise recruitment was conducted in nine nationwide tertiary care centres undertaking high-volume robotic surgery. We aimed to randomise 50 men with synchronous oligo-metastatic prostate cancer within an 18-month recruitment period to SOC systemic therapy vs SOC plus RP (intervention arm). The main outcome measures were: ability to randomise patients, optimised by a QRI; EuroQoL five Dimensions five Levels (EQ-5D-5L) questionnaires to capture quality-of-life (QoL) data at baseline and 3 months post-randomisation; routine clinicopathological assessment to capture adverse events and prostate-specific antigen in both arms, plus standard perioperative parameters in the surgical arm. RESULTS: A total of 51 men were randomised within 14 months (one was subsequently deemed ineligible), with 60-83% accrual rate in centres that recruited at least two patients. All patients completed the trial follow-up; one patient in the intervention arm subsequently did not undergo the surgical intervention and one in the SOC arm refused all therapies. The QRI positively impacted recruitment. QoL data showed similarly high functioning in both study arms. Surgery for men with oligo-metastatic prostate cancer was found to be safe and had similar impact on early functional outcomes as surgery for standard indication. CONCLUSION: It is feasible to randomise men with synchronous oligo-metastatic prostate cancer to a surgical intervention in addition to standard systemic therapies. While surgery appeared safe with no substantial impact on QoL in this feasibility study, a large randomised controlled trial is now warranted to examine treatment effectiveness of this additional component in the multimodality management of oligo-metastatic prostate cancer.
Assuntos
Neoplasias da Próstata , Qualidade de Vida , Estudos de Viabilidade , Humanos , Masculino , Estudos Prospectivos , Prostatectomia/métodos , Neoplasias da Próstata/patologia , Resultado do TratamentoRESUMO
OBJECTIVES: The purpose of this study was to establish whether an artificially intelligent (AI) system can be developed to automate stress echocardiography analysis and support clinician interpretation. BACKGROUND: Coronary artery disease is the leading global cause of mortality and morbidity and stress echocardiography remains one of the most commonly used diagnostic imaging tests. METHODS: An automated image processing pipeline was developed to extract novel geometric and kinematic features from stress echocardiograms collected as part of a large, United Kingdom-based prospective, multicenter, multivendor study. An ensemble machine learning classifier was trained, using the extracted features, to identify patients with severe coronary artery disease on invasive coronary angiography. The model was tested in an independent U.S. STUDY: How availability of an AI classification might impact clinical interpretation of stress echocardiograms was evaluated in a randomized crossover reader study. RESULTS: Acceptable classification accuracy for identification of patients with severe coronary artery disease in the training data set was achieved on cross-fold validation based on 31 unique geometric and kinematic features, with a specificity of 92.7% and a sensitivity of 84.4%. This accuracy was maintained in the independent validation data set. The use of the AI classification tool by clinicians increased inter-reader agreement and confidence as well as sensitivity for detection of disease by 10% to achieve an area under the receiver-operating characteristic curve of 0.93. CONCLUSIONS: Automated analysis of stress echocardiograms is possible using AI and provision of automated classifications to clinicians when reading stress echocardiograms could improve accuracy, inter-reader agreement, and reader confidence.
Assuntos
Doença da Artéria Coronariana , Inteligência Artificial , Doença da Artéria Coronariana/diagnóstico por imagem , Ecocardiografia/métodos , Humanos , Valor Preditivo dos Testes , Estudos ProspectivosRESUMO
Exome sequencing in diabetes presents a diagnostic challenge because depending on frequency, functional impact, and genomic and environmental contexts, HNF1A variants can cause maturity-onset diabetes of the young (MODY), increase type 2 diabetes risk, or be benign. A correct diagnosis matters as it informs on treatment, progression, and family risk. We describe a multi-dimensional functional dataset of 73 HNF1A missense variants identified in exomes of 12,940 individuals. Our aim was to develop an analytical framework for stratifying variants along the HNF1A phenotypic continuum to facilitate diagnostic interpretation. HNF1A variant function was determined by four different molecular assays. Structure of the multi-dimensional dataset was explored using principal component analysis, k-means, and hierarchical clustering. Weights for tissue-specific isoform expression and functional domain were integrated. Functionally annotated variant subgroups were used to re-evaluate genetic diagnoses in national MODY diagnostic registries. HNF1A variants demonstrated a range of behaviors across the assays. The structure of the multi-parametric data was shaped primarily by transactivation. Using unsupervised learning methods, we obtained high-resolution functional clusters of the variants that separated known causal MODY variants from benign and type 2 diabetes risk variants and led to reclassification of 4% and 9% of HNF1A variants identified in the UK and Norway MODY diagnostic registries, respectively. Our proof-of-principle analyses facilitated informative stratification of HNF1A variants along the continuum, allowing improved evaluation of clinical significance, management, and precision medicine in diabetes clinics. Transcriptional activity appears a superior readout supporting pursuit of transactivation-centric experimental designs for high-throughput functional screens.
Assuntos
Diabetes Mellitus Tipo 2/genética , Predisposição Genética para Doença , Fator 1-alfa Nuclear de Hepatócito/genética , Mutação de Sentido Incorreto , Sistema de Registros , Aprendizado de Máquina não Supervisionado , Adolescente , Adulto , Alelos , Criança , Análise por Conglomerados , Conjuntos de Dados como Assunto , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/epidemiologia , Diabetes Mellitus Tipo 2/patologia , Feminino , Expressão Gênica , Humanos , Masculino , Noruega/epidemiologia , Fenótipo , Análise de Componente Principal , Reino Unido/epidemiologia , Sequenciamento do Exoma , Adulto JovemRESUMO
BACKGROUND: Magnetic resonance cholangiopancreatography (MRCP) is an important tool for noninvasive imaging of biliary disease, however, its assessment is currently subjective, resulting in the need for objective biomarkers. PURPOSE: To investigate the accuracy, scan/rescan repeatability, and cross-scanner reproducibility of a novel quantitative MRCP tool on phantoms and in vivo. Additionally, to report normative ranges derived from the healthy cohort for duct measurements and tree-level summary metrics. STUDY TYPE: Prospective. PHANTOMS/SUBJECTS: Phantoms: two bespoke designs, one with varying tube-width, curvature, and orientation, and one exhibiting a complex structure based on a real biliary tree. Subjects Twenty healthy volunteers, 10 patients with biliary disease, and 10 with nonbiliary liver disease. SEQUENCE/FIELD STRENGTH: MRCP data were acquired using heavily T2 -weighted 3D multishot fast/turbo spin echo acquisitions at 1.5T and 3T. ASSESSMENT: Digital instances of the phantoms were synthesized with varying resolution and signal-to-noise ratio. Physical 3D-printed phantoms were scanned across six scanners (two field strengths for each of three manufacturers). Human subjects were imaged on four scanners (two fieldstrengths for each of two manufacturers). STATISTICAL TESTS: Bland-Altman analysis and repeatability coefficient (RC). RESULTS: Accuracy of the diameter measurement approximated the scanning resolution, with 95% limits of agreement (LoA) from -1.1 to 1.0 mm. Excellent phantom repeatability was observed, with LoA from -0.4 to 0.4 mm. Good reproducibility was observed across the six scanners for both phantoms, with a range of LoA from -1.1 to 0.5 mm. Inter- and intraobserver agreement was high. Quantitative MRCP detected strictures and dilatations in the phantom with 76.6% and 85.9% sensitivity and 100% specificity in both. Patients and healthy volunteers exhibited significant differences in metrics including common bile duct (CBD) maximum diameter (7.6 mm vs. 5.2 mm P = 0.002), and overall biliary tree volume 12.36 mL vs. 4.61 mL, P = 0.0026). DATA CONCLUSION: The results indicate that quantitative MRCP provides accurate, repeatable, and reproducible measurements capable of objectively assessing cholangiopathic change. Evidence Level: 1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2020;52:807-820.
Assuntos
Colangiopancreatografia por Ressonância Magnética , Processamento de Imagem Assistida por Computador , Humanos , Imageamento por Ressonância Magnética , Imagens de Fantasmas , Estudos Prospectivos , Reprodutibilidade dos TestesRESUMO
OBJECTIVE: Heterozygous loss-of-function mutations in HNF1A cause maturity-onset diabetes of the young (MODY). Affected individuals can be treated with low-dose sulfonylureas. Individuals with homozygous HNF1A mutations causing MODY have not been reported. RESEARCH DESIGN AND METHODS: We phenotyped a kindred with young-onset diabetes and performed molecular genetic testing, a mixed meal tolerance test, a sulfonylurea challenge, and in vitro assays to assess variant protein function. RESULTS: A homozygous HNF1A variant (p.A251T) was identified in three insulin-treated family members diagnosed with diabetes before 20 years of age. Those with the homozygous variant had low hs-CRP levels (0.2-0.8 mg/L), and those tested demonstrated sensitivity to sulfonylurea given at a low dose, completely transitioning off insulin. In silico modeling predicted a variant of unknown significance; however, in vitro studies supported a modest reduction in transactivation potential (79% of that for the wild type; P < 0.05) in the absence of endogenous HNF1A. CONCLUSIONS: Homozygous hypomorphic HNF1A variants are a cause of HNF1A-MODY. We thus expand the allelic spectrum of variants in dominant genes causing diabetes.
Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/genética , Fator 1-alfa Nuclear de Hepatócito/genética , Compostos de Sulfonilureia/uso terapêutico , Adulto , Idade de Início , Alelos , Diabetes Mellitus/tratamento farmacológico , Diabetes Mellitus/epidemiologia , Diabetes Mellitus/genética , Diabetes Mellitus Tipo 2/epidemiologia , Resistência a Medicamentos/efeitos dos fármacos , Resistência a Medicamentos/genética , Feminino , Homozigoto , Humanos , Hipoglicemiantes/uso terapêutico , Insulina/uso terapêutico , Mutação , Mutação de Sentido Incorreto , GravidezRESUMO
OBJECTIVE/BACKGROUND: Up to 25% of patients undergoing elective endovascular aneurysm repair (EVAR) develop acute kidney injury (AKI), which is associated with short and long-term morbidity and mortality. There is no high quality randomised evidence regarding prevention of EVAR related AKI. METHODS: A novel AKI prevention strategy for EVAR was devised, based on best evidence and an expert consensus group. This included a bolus of high dose sodium bicarbonate (NaHCO3) immediately before EVAR (1 mL/kg of 8.4% NaHCO3) and standardised crystalloid based hydration pre- and post-EVAR. A pilot/feasibility randomised controlled trial (RCT) was performed in two centres to assess the safety of the intervention, potential impact on AKI prevention, and feasibility of a national RCT; the primary end point was the proportion of eligible patients recruited into the study. AKI was defined using "Kidney Disease Improving Global Outcomes" and "Acute Kidney Injury Network" criteria based on National Institute for Health and Clinical Excellence AKI recommendations, using serum creatinine and hourly urine output. RESULTS: Fifty-eight patients (84% of those screened; median age 75 years [range 57-89 years], 10% female) were randomised to receive the standardised intravenous hydration with (intervention) or without (control) NaHCO3. Groups were comparable in terms of AKI risk factors; 56 of 58 participants had a device with suprarenal fixation. Overall, 33% of patients in the control arm developed AKI versus 7% in the intervention arm (as treated analysis). None of the patients receiving NaHCO3 developed a serious intervention related adverse event; five patients did not attend their 30 day follow-up. CONCLUSION: Bolus high dose NaHCO3 and hydration is a promising EVAR related AKI prevention method. This trial has confirmed the feasibility of delivering a definitive large RCT to confirm the efficacy of this novel intervention, in preventing EVAR related AKI.
Assuntos
Injúria Renal Aguda , Bicarbonatos/administração & dosagem , Procedimentos Endovasculares/efeitos adversos , Hidratação/métodos , Complicações Pós-Operatórias , Injúria Renal Aguda/diagnóstico , Injúria Renal Aguda/etiologia , Injúria Renal Aguda/prevenção & controle , Administração Intravenosa , Idoso , Aneurisma da Aorta Abdominal/cirurgia , Soluções Tampão , Creatinina/análise , Monitoramento de Medicamentos/métodos , Procedimentos Endovasculares/métodos , Estudos de Viabilidade , Feminino , Humanos , Masculino , Projetos Piloto , Complicações Pós-Operatórias/diagnóstico , Complicações Pós-Operatórias/prevenção & controle , Soluções para Reidratação/administração & dosagemRESUMO
INTRODUCTION: Most studies seeking common variant associations with type 2 diabetes (T2D) have focused on individuals of European ancestry. These discoveries need to be evaluated in other major ancestral groups, to understand ethnic differences in predisposition, and establish whether these contribute to variation in T2D prevalence and presentation. This study aims to establish whether common variants conferring T2D-risk in Europeans contribute to T2D-susceptibility in the South Asian population of Sri Lanka. METHODOLOGY: Lead single nucleotide polymorphism (SNPs) at 37 T2D-risk loci attaining genome-wide significance in Europeans were genotyped in 878 T2D cases and 1523 normoglycaemic controls from Sri Lanka. Association testing was performed by logistic regression adjusting for age and sex and by the Cochran-Mantel-Haenszel test after stratifying according to self-identified ethnolinguistic subgroup. A weighted genetic risk score was generated to examine the combined effect of these SNPs on T2D-risk in the Sri Lankan population. RESULTS: Of the 36 SNPs passing quality control, sixteen showed nominal (p<0.05) association in Sri Lankan samples, fifteen of those directionally-consistent with the original signal. Overall, these association findings were robust to analyses that accounted for membership of ethnolinguistic subgroups. Overall, the odds ratios for 31 of the 36 SNPs were directionally-consistent with those observed in Europeans (pâ=â3.2×10(-6)). Allelic odds ratios and risk allele frequencies in Sri Lankan subjects were not systematically different to those reported in Europeans. Genetic risk score and risk of T2D were strongly related in Sri Lankans (per allele OR 1.10 [95%CI 1.08-1.13], pâ=â1.2×10(-17)). CONCLUSION: Our data indicate that most T2D-risk variants identified in Europeans have similar effects in South Asians from Sri Lanka, and that systematic difference in common variant associations are unlikely to explain inter-ethnic differences in prevalence or presentation of T2D.
Assuntos
Diabetes Mellitus Tipo 2/etnologia , Diabetes Mellitus Tipo 2/genética , Polimorfismo de Nucleotídeo Único , População Branca/etnologia , Sudeste Asiático/etnologia , Estudos de Casos e Controles , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Genótipo , Humanos , Modelos Logísticos , Sri Lanka/etnologia , População Branca/genéticaRESUMO
Favorable associations between magnesium intake and glycemic traits, such as fasting glucose and insulin, are observed in observational and clinical studies, but whether genetic variation affects these associations is largely unknown. We hypothesized that single nucleotide polymorphisms (SNPs) associated with either glycemic traits or magnesium metabolism affect the association between magnesium intake and fasting glucose and insulin. Fifteen studies from the CHARGE (Cohorts for Heart and Aging Research in Genomic Epidemiology) Consortium provided data from up to 52,684 participants of European descent without known diabetes. In fixed-effects meta-analyses, we quantified 1) cross-sectional associations of dietary magnesium intake with fasting glucose (mmol/L) and insulin (ln-pmol/L) and 2) interactions between magnesium intake and SNPs related to fasting glucose (16 SNPs), insulin (2 SNPs), or magnesium (8 SNPs) on fasting glucose and insulin. After adjustment for age, sex, energy intake, BMI, and behavioral risk factors, magnesium (per 50-mg/d increment) was inversely associated with fasting glucose [ß = -0.009 mmol/L (95% CI: -0.013, -0.005), P < 0.0001] and insulin [-0.020 ln-pmol/L (95% CI: -0.024, -0.017), P < 0.0001]. No magnesium-related SNP or interaction between any SNP and magnesium reached significance after correction for multiple testing. However, rs2274924 in magnesium transporter-encoding TRPM6 showed a nominal association (uncorrected P = 0.03) with glucose, and rs11558471 in SLC30A8 and rs3740393 near CNNM2 showed a nominal interaction (uncorrected, both P = 0.02) with magnesium on glucose. Consistent with other studies, a higher magnesium intake was associated with lower fasting glucose and insulin. Nominal evidence of TRPM6 influence and magnesium interaction with select loci suggests that further investigation is warranted.
Assuntos
Glicemia/metabolismo , Loci Gênicos , Insulina/sangue , Magnésio/farmacologia , Polimorfismo de Nucleotídeo Único , Oligoelementos/farmacologia , Glicemia/genética , Feminino , Humanos , Insulina/genética , Magnésio/administração & dosagem , Magnésio/metabolismo , Masculino , Canais de Cátion TRPM/genética , Oligoelementos/administração & dosagem , Oligoelementos/metabolismoRESUMO
We performed a genome-wide association study (GWAS) and a multistage meta-analysis of type 2 diabetes (T2D) in Punjabi Sikhs from India. Our discovery GWAS in 1,616 individuals (842 case subjects) was followed by in silico replication of the top 513 independent single nucleotide polymorphisms (SNPs) (P < 10⻳) in Punjabi Sikhs (n = 2,819; 801 case subjects). We further replicated 66 SNPs (P < 10â»4) through genotyping in a Punjabi Sikh sample (n = 2,894; 1,711 case subjects). On combined meta-analysis in Sikh populations (n = 7,329; 3,354 case subjects), we identified a novel locus in association with T2D at 13q12 represented by a directly genotyped intronic SNP (rs9552911, P = 1.82 × 10â»8) in the SGCG gene. Next, we undertook in silico replication (stage 2b) of the top 513 signals (P < 10⻳) in 29,157 non-Sikh South Asians (10,971 case subjects) and de novo genotyping of up to 31 top signals (P < 10â»4) in 10,817 South Asians (5,157 case subjects) (stage 3b). In combined South Asian meta-analysis, we observed six suggestive associations (P < 10â»5 to < 10â»7), including SNPs at HMG1L1/CTCFL, PLXNA4, SCAP, and chr5p11. Further evaluation of 31 top SNPs in 33,707 East Asians (16,746 case subjects) (stage 3c) and 47,117 Europeans (8,130 case subjects) (stage 3d), and joint meta-analysis of 128,127 individuals (44,358 case subjects) from 27 multiethnic studies, did not reveal any additional loci nor was there any evidence of replication for the new variant. Our findings provide new evidence on the presence of a population-specific signal in relation to T2D, which may provide additional insights into T2D pathogenesis.
Assuntos
Diabetes Mellitus Tipo 2/genética , Polimorfismo de Nucleotídeo Único , Sarcoglicanas/genética , Povo Asiático , Estudos de Casos e Controles , Estudos de Coortes , Consanguinidade , Diabetes Mellitus Tipo 2/metabolismo , Europa (Continente) , Feminino , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Humanos , Índia , Masculino , Sarcoglicanas/metabolismoRESUMO
A recent genome-wide association study identified hepatocyte nuclear factor 1-α (HNF1A) as a key regulator of fucosylation. We hypothesized that loss-of-function HNF1A mutations causal for maturity-onset diabetes of the young (MODY) would display altered fucosylation of N-linked glycans on plasma proteins and that glycan biomarkers could improve the efficiency of a diagnosis of HNF1A-MODY. In a pilot comparison of 33 subjects with HNF1A-MODY and 41 subjects with type 2 diabetes, 15 of 29 glycan measurements differed between the two groups. The DG9-glycan index, which is the ratio of fucosylated to nonfucosylated triantennary glycans, provided optimum discrimination in the pilot study and was examined further among additional subjects with HNF1A-MODY (n = 188), glucokinase (GCK)-MODY (n = 118), hepatocyte nuclear factor 4-α (HNF4A)-MODY (n = 40), type 1 diabetes (n = 98), type 2 diabetes (n = 167), and nondiabetic controls (n = 98). The DG9-glycan index was markedly lower in HNF1A-MODY than in controls or other diabetes subtypes, offered good discrimination between HNF1A-MODY and both type 1 and type 2 diabetes (C statistic ≥ 0.90), and enabled us to detect three previously undetected HNF1A mutations in patients with diabetes. In conclusion, glycan profiles are altered substantially in HNF1A-MODY, and the DG9-glycan index has potential clinical value as a diagnostic biomarker of HNF1A dysfunction.
Assuntos
Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 2/genética , Fator 1-alfa Nuclear de Hepatócito/metabolismo , Polissacarídeos/sangue , Adolescente , Adulto , Biomarcadores , Feminino , Regulação da Expressão Gênica/fisiologia , Fator 1-alfa Nuclear de Hepatócito/genética , Humanos , Masculino , Pessoa de Meia-Idade , Mutação de Sentido Incorreto , Polimorfismo de Nucleotídeo Único , Polissacarídeos/metabolismo , Reprodutibilidade dos Testes , Adulto JovemRESUMO
Whether loci that influence fasting glucose (FG) and fasting insulin (FI) levels, as identified by genome-wide association studies, modify associations of diet with FG or FI is unknown. We utilized data from 15 U.S. and European cohort studies comprising 51,289 persons without diabetes to test whether genotype and diet interact to influence FG or FI concentration. We constructed a diet score using study-specific quartile rankings for intakes of whole grains, fish, fruits, vegetables, and nuts/seeds (favorable) and red/processed meats, sweets, sugared beverages, and fried potatoes (unfavorable). We used linear regression within studies, followed by inverse-variance-weighted meta-analysis, to quantify 1) associations of diet score with FG and FI levels and 2) interactions of diet score with 16 FG-associated loci and 2 FI-associated loci. Diet score (per unit increase) was inversely associated with FG (ß = -0.004 mmol/L, 95% confidence interval: -0.005, -0.003) and FI (ß = -0.008 ln-pmol/L, 95% confidence interval: -0.009, -0.007) levels after adjustment for demographic factors, lifestyle, and body mass index. Genotype variation at the studied loci did not modify these associations. Healthier diets were associated with lower FG and FI concentrations regardless of genotype at previously replicated FG- and FI-associated loci. Studies focusing on genomic regions that do not yield highly statistically significant associations from main-effect genome-wide association studies may be more fruitful in identifying diet-gene interactions.
Assuntos
Glicemia/metabolismo , Metabolismo dos Carboidratos/genética , Dieta , Interação Gene-Ambiente , Genótipo , Homeostase/genética , Insulina/sangue , Biomarcadores/sangue , Glicemia/genética , Inquéritos sobre Dietas , Jejum , Marcadores Genéticos , Estudo de Associação Genômica Ampla , Homeostase/fisiologia , Humanos , Insulina/genética , Modelos Lineares , Polimorfismo de Nucleotídeo ÚnicoRESUMO
Sequence-based variation in gene expression is a key driver of disease risk. Common variants regulating expression in cis have been mapped in many expression quantitative trait locus (eQTL) studies, typically in single tissues from unrelated individuals. Here, we present a comprehensive analysis of gene expression across multiple tissues conducted in a large set of mono- and dizygotic twins that allows systematic dissection of genetic (cis and trans) and non-genetic effects on gene expression. Using identity-by-descent estimates, we show that at least 40% of the total heritable cis effect on expression cannot be accounted for by common cis variants, a finding that reveals the contribution of low-frequency and rare regulatory variants with respect to both transcriptional regulation and complex trait susceptibility. We show that a substantial proportion of gene expression heritability is trans to the structural gene, and we identify several replicating trans variants that act predominantly in a tissue-restricted manner and may regulate the transcription of many genes.
Assuntos
Mapeamento Cromossômico , Regulação da Expressão Gênica , Transcrição Gênica , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Interação Gene-Ambiente , Ligação Genética , Humanos , Linfócitos/metabolismo , Pessoa de Meia-Idade , Modelos Genéticos , Especificidade de Órgãos , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas , Pele/metabolismo , Gordura Subcutânea/metabolismoRESUMO
We carried out a genome-wide association study of type-2 diabetes (T2D) in individuals of South Asian ancestry. Our discovery set included 5,561 individuals with T2D (cases) and 14,458 controls drawn from studies in London, Pakistan and Singapore. We identified 20 independent SNPs associated with T2D at P < 10(-4) for testing in a replication sample of 13,170 cases and 25,398 controls, also all of South Asian ancestry. In the combined analysis, we identified common genetic variants at six loci (GRB14, ST6GAL1, VPS26A, HMG20A, AP3S2 and HNF4A) newly associated with T2D (P = 4.1 × 10(-8) to P = 1.9 × 10(-11)). SNPs at GRB14 were also associated with insulin sensitivity (P = 5.0 × 10(-4)), and SNPs at ST6GAL1 and HNF4A were also associated with pancreatic beta-cell function (P = 0.02 and P = 0.001, respectively). Our findings provide additional insight into mechanisms underlying T2D and show the potential for new discovery from genetic association studies in South Asians, a population with increased susceptibility to T2D.
Assuntos
Diabetes Mellitus Tipo 2/genética , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Locos de Características Quantitativas , Povo Asiático/genética , Estudos de Casos e Controles , Feminino , Regulação da Expressão Gênica , Genética Populacional , Genoma Humano , Humanos , Desequilíbrio de Ligação , Londres , Masculino , Paquistão , Polimorfismo de Nucleotídeo Único , SingapuraRESUMO
OBJECTIVE: To investigate whether associations of common genetic variants recently identified for fasting glucose or insulin levels in nondiabetic adults are detectable in healthy children and adolescents. RESEARCH DESIGN AND METHODS: A total of 16 single nucleotide polymorphisms (SNPs) associated with fasting glucose were genotyped in six studies of children and adolescents of European origin, including over 6,000 boys and girls aged 9-16 years. We performed meta-analyses to test associations of individual SNPs and a weighted risk score of the 16 loci with fasting glucose. RESULTS: Nine loci were associated with glucose levels in healthy children and adolescents, with four of these associations reported in previous studies and five reported here for the first time (GLIS3, PROX1, SLC2A2, ADCY5, and CRY2). Effect sizes were similar to those in adults, suggesting age-independent effects of these fasting glucose loci. Children and adolescents carrying glucose-raising alleles of G6PC2, MTNR1B, GCK, and GLIS3 also showed reduced ß-cell function, as indicated by homeostasis model assessment of ß-cell function. Analysis using a weighted risk score showed an increase [ß (95% CI)] in fasting glucose level of 0.026 mmol/L (0.021-0.031) for each unit increase in the score. CONCLUSIONS: Novel fasting glucose loci identified in genome-wide association studies of adults are associated with altered fasting glucose levels in healthy children and adolescents with effect sizes comparable to adults. In nondiabetic adults, fasting glucose changes little over time, and our results suggest that age-independent effects of fasting glucose loci contribute to long-term interindividual differences in glucose levels from childhood onwards.
Assuntos
Glicemia/genética , Jejum/sangue , Loci Gênicos/genética , Adenilil Ciclases/genética , Adolescente , Criança , Criptocromos/genética , Proteínas de Ligação a DNA , Feminino , Estudo de Associação Genômica Ampla , Quinases do Centro Germinativo , Transportador de Glucose Tipo 2/genética , Glucose-6-Fosfatase/genética , Proteínas de Homeodomínio/genética , Humanos , Masculino , Polimorfismo de Nucleotídeo Único/genética , Proteínas Serina-Treonina Quinases/genética , Proteínas Repressoras , Transativadores , Fatores de Transcrição/genética , Proteínas Supressoras de Tumor/genéticaRESUMO
While there have been studies exploring regulatory variation in one or more tissues, the complexity of tissue-specificity in multiple primary tissues is not yet well understood. We explore in depth the role of cis-regulatory variation in three human tissues: lymphoblastoid cell lines (LCL), skin, and fat. The samples (156 LCL, 160 skin, 166 fat) were derived simultaneously from a subset of well-phenotyped healthy female twins of the MuTHER resource. We discover an abundance of cis-eQTLs in each tissue similar to previous estimates (858 or 4.7% of genes). In addition, we apply factor analysis (FA) to remove effects of latent variables, thus more than doubling the number of our discoveries (1,822 eQTL genes). The unique study design (Matched Co-Twin Analysis--MCTA) permits immediate replication of eQTLs using co-twins (93%-98%) and validation of the considerable gain in eQTL discovery after FA correction. We highlight the challenges of comparing eQTLs between tissues. After verifying previous significance threshold-based estimates of tissue-specificity, we show their limitations given their dependency on statistical power. We propose that continuous estimates of the proportion of tissue-shared signals and direct comparison of the magnitude of effect on the fold change in expression are essential properties that jointly provide a biologically realistic view of tissue-specificity. Under this framework we demonstrate that 30% of eQTLs are shared among the three tissues studied, while another 29% appear exclusively tissue-specific. However, even among the shared eQTLs, a substantial proportion (10%-20%) have significant differences in the magnitude of fold change between genotypic classes across tissues. Our results underline the need to account for the complexity of eQTL tissue-specificity in an effort to assess consequences of such variants for complex traits.
Assuntos
Tecido Adiposo/metabolismo , Genes Reguladores/genética , Locos de Características Quantitativas/genética , Pele/metabolismo , Linhagem Celular , Células Cultivadas , Interpretação Estatística de Dados , Feminino , Perfilação da Expressão Gênica , Genótipo , Humanos , Especificidade de Órgãos/genética , Fenótipo , GêmeosRESUMO
To identify genetic variants associated with birth weight, we meta-analyzed six genome-wide association (GWA) studies (n = 10,623 Europeans from pregnancy/birth cohorts) and followed up two lead signals in 13 replication studies (n = 27,591). rs900400 near LEKR1 and CCNL1 (P = 2 x 10(-35)) and rs9883204 in ADCY5 (P = 7 x 10(-15)) were robustly associated with birth weight. Correlated SNPs in ADCY5 were recently implicated in regulation of glucose levels and susceptibility to type 2 diabetes, providing evidence that the well-described association between lower birth weight and subsequent type 2 diabetes has a genetic component, distinct from the proposed role of programming by maternal nutrition. Using data from both SNPs, we found that the 9% of Europeans carrying four birth weight-lowering alleles were, on average, 113 g (95% CI 89-137 g) lighter at birth than the 24% with zero or one alleles (P(trend) = 7 x 10(-30)). The impact on birth weight is similar to that of a mother smoking 4-5 cigarettes per day in the third trimester of pregnancy.