Publications by authors named "Doug Speed"

Heart failure (HF) is a major contributor to global morbidity and mortality. While distinct clinical subtypes, defined by etiology and left ventricular ejection fraction, are well recognized, their genetic determinants remain inadequately understood. In this study, we report a genome-wide association study of HF and its subtypes in a sample of 1.

View Article and Find Full Text PDF
Article Synopsis
  • Dilated cardiomyopathy (DCM) is a major cause of heart failure, and this study analyzes genetic factors by examining 14,256 DCM cases and 36,203 participants from the UK Biobank for related traits.
  • Researchers discovered 80 genomic risk loci and pinpointed 62 potential effector genes tied to DCM, including some linked to rare variants.
  • The study uses advanced transcriptomics to explore how cellular functions contribute to DCM, showing that polygenic scores can help predict the disease in the general population and emphasize the importance of genetic testing and development of precise treatments.
View Article and Find Full Text PDF

The relative magnitude of additive genetic vs. residual variation for fitness traits is important in models for predicting the rate of evolution and population persistence in response to changes in the environment. In many annual plants, lifetime reproductive fitness is correlated with end-of-season plant biomass, which can vary significantly from plant to plant in the same population.

View Article and Find Full Text PDF

We propose TetraHer, a method for estimating the liability heritability of binary phenotypes. TetraHer has five key features. First, it can be applied to data from complex pedigrees that contain multiple types of relationships.

View Article and Find Full Text PDF
Article Synopsis
  • The study addresses limitations in genome-wide association studies (GWAS), such as multiple testing and ignoring variant correlations, by using a sparse Bayesian learning model specifically for bipolar disorder (BD) genetics.
  • Analyzed data from 1998 BD cases and 1500 controls resulted in the identification of 13 genetic variants associated with BD, including previously highlighted ones, and some variants were linked to blood parameters.
  • The findings suggest that applying Bayesian models can enhance the understanding of BD genetics even in smaller samples, indicating a need for further research on related variations.
View Article and Find Full Text PDF

Objective: Mendelian randomization studies report a bi-directional relation between cigarette smoking and mental disorders, yet from a clinical standpoint, mental disorders are the focus of treatment. Here, we used an event history framework to understand their evolution in the life course. Our objective was to estimate the relative contribution of genetic predispositions and self-reported smoking status (never, former, and present smoker) to hospitalizations for major depression, bipolar disorder, and schizophrenia.

View Article and Find Full Text PDF
Article Synopsis
  • Volunteer-based studies like the UK Biobank often lack representative samples, impacting genetic research outcomes.
  • Researchers derived participation probabilities from 14 variables to conduct weighted genome-wide association analyses on 19 traits, revealing that increased representativeness altered SNP effect sizes and identified new associations for 12 traits.
  • While heritability estimates varied little with weighting, significant discrepancies were found in genetic correlations and Mendelian randomization estimates for socio-behavioral traits, highlighting the need for more representative biobank samples in genetic studies related to behavior and social outcomes.
View Article and Find Full Text PDF

We present LDAK-GBAT, a tool for gene-based association testing using summary statistics from genome-wide association studies that is computationally efficient, produces well-calibrated p values, and is significantly more powerful than existing tools. LDAK-GBAT takes approximately 30 min to analyze imputed data (2.9M common, genic SNPs), requiring less than 10 Gb memory.

View Article and Find Full Text PDF

Bipolar disorder is associated with increased body mass index (BMI), but it remains undetermined if this association is causal and, if so, in which direction it goes. Here, we sought to answer these questions using bidirectional two-sample Mendelian randomization, a method from genetic epidemiology that uses data from genome-wide association studies (GWAS) to examine whether a risk factor is causal for an outcome METHODS: We used summary statistics from GWAS of bipolar disorder and BMI conducted using data collected by the Psychiatric Genomics Consortium and the UK Biobank, respectively. The genetic instrument for bipolar disorder contained 53 SNPs and explained 0.

View Article and Find Full Text PDF

Visceral leishmaniasis (VL) is a potentially fatal disease caused mainly by Leishmania infantum in South America and Leishmania donovani in Asia and Africa. Disease outcomes have been associated with patient genotype, nutrition, age, sex, comorbidities, and coinfections. In this study, we examine the effects of parasite genetic variation on VL disease severity in Brazil.

View Article and Find Full Text PDF
Article Synopsis
  • Equine recurrent uveitis (ERU) is a serious eye disease affecting horses, particularly common in Appaloosas, where a chronic form called insidious uveitis occurs.
  • This study aimed to estimate the heritability of insidious uveitis in Appaloosas by analyzing genetic data from affected and unaffected horses, finding strong evidence for genetic factors influencing the disease.
  • The heritability estimates were high (0.95 to 1.74), indicating that other genetic loci beyond the known coat pattern gene (LP) also contribute to the risk of developing this condition, which could inform better breeding and treatment strategies in the future.
View Article and Find Full Text PDF

Missing heritability in genome-wide association studies defines a major problem in genetic analyses of complex biological traits. The solution to this problem is to identify all causal genetic variants and to measure their individual contributions. Here we report a graph pangenome of tomato constructed by precisely cataloguing more than 19 million variants from 838 genomes, including 32 new reference-level genome assemblies.

View Article and Find Full Text PDF

Complex-trait genetics has advanced dramatically through methods to estimate the heritability tagged by SNPs, both genome-wide and in genomic regions of interest such as those defined by functional annotations. The models underlying many of these analyses are inadequate, and consequently many SNP-heritability results published to date are inaccurate. Here, we review the modelling issues, both for analyses based on individual genotype data and association test statistics, highlighting the role of a low-dimensional model for the heritability of each SNP.

View Article and Find Full Text PDF

Objective: While most of the variation in thyroid function is determined by genetic factors, single nucleotide polymorphisms (SNPs) identified via genome-wide association analyses have only explained ~5% to 9% of this variance so far. Most SNPs were in or nearby genes with no known role in thyroid hormone (TH) regulation. Therefore, we performed a large-scale candidate gene study investigating the effect of common genetic variation in established TH regulating genes on serum thyrotropin [thyroid-stimulating hormone (TSH)] and thyroxine (FT4) concentrations.

View Article and Find Full Text PDF

Whole-genome sequencing has facilitated genome-wide analyses of association, prediction and heritability in many organisms. However, such analyses in bacteria are still in their infancy, being limited by difficulties including genome plasticity and strong population structure. Here we propose a suite of methods including linear mixed models, elastic net and LD-score regression, adapted to bacterial traits using innovations such as frequency-based allele coding, both insertion/deletion and nucleotide testing and heritability partitioning.

View Article and Find Full Text PDF

Here, with the example of common copy number variation (CNV) in the gene, we present an important piece of work in the field of CNV detection, that is, CNV association with complex human traits such as H NMR metabolomic phenotypes and an example of functional characterization of CNVs among human induced pluripotent stem cells (HipSci). We report exon 11 (ENSE00003720745) as a pleiotropic locus associated with metabolomic regulation and show that its biology is associated with several metabolic diseases such as type 2 diabetes (T2D) and cancer. Our results further demonstrate the power of multivariate association models over univariate methods and define metabolomic signatures for variants in .

View Article and Find Full Text PDF

Most existing tools for constructing genetic prediction models begin with the assumption that all genetic variants contribute equally towards the phenotype. However, this represents a suboptimal model for how heritability is distributed across the genome. Therefore, we develop prediction tools that allow the user to specify the heritability model.

View Article and Find Full Text PDF

Cannabis use is associated with a number of psychiatric disorders; however, the causal nature of these associations has been difficult to establish. Mendelian randomization (MR) offers a way to infer causality between exposures with known genetic predictors (genome-wide significant single nucleotide polymorphisms [SNPs]) and outcomes of interest. MR has previously been applied to investigate the relationship between lifetime cannabis use (having ever used cannabis) and schizophrenia, depression, and attention deficit hyperactivity disorder (ADHD), but not bipolar disorder, representing a gap in the literature.

View Article and Find Full Text PDF
Article Synopsis
  • Estimating narrow-sense heritability in mixed populations is challenging, but the study used simulations to assess linear mixed-model frameworks on cohorts from Greenland compared to unadmixed Danes.
  • When analyzing Greenlandic sibling pairs, a model incorporating both genetic relationship matrices yielded accurate heritability estimates, while using each matrix alone caused biases.
  • The authors suggest a PCA-based adjustment for better accuracy and found that, in general, Greenlanders have lower heritability for traits like height when compared to Europeans.
View Article and Find Full Text PDF

There is currently much debate regarding the best model for how heritability varies across the genome. The authors of GCTA recommend the GCTA-LDMS-I model, the authors of LD Score Regression recommend the Baseline LD model, and we have recommended the LDAK model. Here we provide a statistical framework for assessing heritability models using summary statistics from genome-wide association studies.

View Article and Find Full Text PDF
Article Synopsis
  • Early childhood growth patterns are linked to health in adulthood, but the genetic influences and developmental stages remain unclear.
  • This study uses genome-wide association studies and various analyses to explore how genetics of early growth relate to adult health, finding significant connections between child and adult body mass index (BMI).
  • The research also reveals distinct genetic factors influencing peak BMI during infancy, implying different strategies may be needed for addressing childhood obesity in prevention efforts.
View Article and Find Full Text PDF

Linkage disequilibrium SCore regression (LDSC) has become a popular approach to estimate confounding bias, heritability, and genetic correlation using only genome-wide association study (GWAS) test statistics. SumHer is a newly introduced alternative with similar aims. We show using theory and simulations that both approaches fail to adequately account for confounding bias, even when the assumed heritability model is correct.

View Article and Find Full Text PDF

Obesity and depression are major public health concerns that are both associated with substantial morbidity and mortality. There is a considerable body of literature linking obesity to the development of depression. Recent studies using Mendelian randomization indicate that this relationship is causal.

View Article and Find Full Text PDF

We present SumHer, software for estimating confounding bias, SNP heritability, enrichments of heritability and genetic correlations using summary statistics from genome-wide association studies. The key difference between SumHer and the existing software LD Score Regression (LDSC) is that SumHer allows the user to specify the heritability model. We apply SumHer to results from 24 large-scale association studies (average sample size 121,000) using our recommended heritability model.

View Article and Find Full Text PDF

Individuals with psychiatric disorders have elevated rates of autoimmune comorbidity and altered immune signaling. It is unclear whether these altered immunological states have a shared genetic basis with those psychiatric disorders. The present study sought to use existing summary-level data from previous genome-wide association studies to determine if commonly varying single nucleotide polymorphisms are shared between psychiatric and immune-related phenotypes.

View Article and Find Full Text PDF

A PHP Error was encountered

Severity: Warning

Message: fopen(/var/lib/php/sessions/ci_sessionj53n7i0pn46fdnp1qm5r8sod40jud24c): Failed to open stream: No space left on device

Filename: drivers/Session_files_driver.php

Line Number: 177

Backtrace:

File: /var/www/html/index.php
Line: 316
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: session_start(): Failed to read session data: user (path: /var/lib/php/sessions)

Filename: Session/Session.php

Line Number: 137

Backtrace:

File: /var/www/html/index.php
Line: 316
Function: require_once