Publications by authors named "Ulirsch J"

Genome-wide association studies (GWAS) help to identify disease-linked genetic variants, but pinpointing the most likely causal genes in GWAS loci remains challenging. Existing GWAS gene prioritization tools are powerful, but often use complex black box models trained on datasets containing unaddressed biases. Here we present CALDERA, a gene prioritization tool that achieves similar or better performance than state-of-the-art methods, but uses just 12 features and a simple logistic regression model with L1 regularization.

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Identifying the causal variants and mechanisms that drive complex traits and diseases remains a core problem in human genetics. The majority of these variants have individually weak effects and lie in non-coding gene-regulatory elements where we lack a complete understanding of how single nucleotide alterations modulate transcriptional processes to affect human phenotypes. To address this, we measured the activity of 221,412 trait-associated variants that had been statistically fine-mapped using a Massively Parallel Reporter Assay (MPRA) in 5 diverse cell-types.

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Fine-mapping aims to identify causal genetic variants for phenotypes. Bayesian fine-mapping algorithms (for example, SuSiE, FINEMAP, ABF and COJO-ABF) are widely used, but assessing posterior probability calibration remains challenging in real data, where model misspecification probably exists, and true causal variants are unknown. We introduce replication failure rate (RFR), a metric to assess fine-mapping consistency by downsampling.

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Article Synopsis
  • Noncoding DNA helps scientists understand how genes work and how they relate to diseases in humans.
  • Researchers studied the DNA of many primates to find specific regulatory parts that are important for gene regulation.
  • They discovered a lot of these regulatory elements in humans that are different from those in other mammals, which can help explain human traits and health issues.
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  • - This study identifies over 13 million interactions between transcriptional enhancers and their target genes across various cell types and tissues, which is crucial for understanding how gene regulation influences diseases.
  • - Utilizing a new predictive model called ENCODE-rE2G, the researchers achieved high accuracy in predicting enhancer-gene interactions, supported by a robust dataset from CRISPR experiments and genetic mapping.
  • - The findings highlight not only the role of enhancers and their contacts with promoters but also additional factors like promoter types and enhancer interactions that affect gene regulation, creating a detailed resource for future genetic research.
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The eQTL Catalogue is an open database of uniformly processed human molecular quantitative trait loci (QTLs). We are continuously updating the resource to further increase its utility for interpreting genetic associations with complex traits. Over the past two years, we have increased the number of uniformly processed studies from 21 to 31 and added X chromosome QTLs for 19 compatible studies.

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  • The study focuses on RNA polymerase II (RNA Pol II) pausing, which is important for gene regulation but difficult to study due to the essential nature of pause-release factors.
  • Researchers found mutations in the SUPT5H gene linked to β-thalassemia that disrupt RNA Pol II's pause release during the transition from progenitor to precursor cells in erythropoiesis (red blood cell formation).
  • These mutations led to delayed differentiation and altered gene expression in erythroid cells, highlighting RNA Pol II pausing's role in coordinating cell cycle progression and differentiation in blood cell development.
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Genome-wide association studies (GWASs) are a valuable tool for understanding the biology of complex human traits and diseases, but associated variants rarely point directly to causal genes. In the present study, we introduce a new method, polygenic priority score (PoPS), that learns trait-relevant gene features, such as cell-type-specific expression, to prioritize genes at GWAS loci. Using a large evaluation set of genes with fine-mapped coding variants, we show that PoPS and the closest gene individually outperform other gene prioritization methods, but observe the best overall performance by combining PoPS with orthogonal methods.

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  • * Individuals with extreme traits or high risk for serious diseases are more effectively identified through a small number of rare variants rather than through numerous common variants that have minimal effects.
  • * By integrating rare variants from related genes into a single genetic risk model, we created a more effective tool for predicting disease risk across different populations, outperforming traditional methods based on common variants.
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  • * Rare mutations in certain genes have a much stronger impact on severe diseases than more common genetic variations.
  • * By using rare variants to create a genetic risk model, we were able to predict disease risk more effectively across different populations compared to traditional methods that rely on common variants.
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  • Splicing QTLs are linked to complex trait associations, but analyzing them is tough due to data normalization making it hard to interpret genetic effects.
  • Strong expression QTLs can appear as weak splicing QTLs, complicating the identification of the true molecular mechanisms involved.
  • The study provides QTL coverage plots for 1.7 million associations, demonstrating that while splicing QTLs are less common, they can effectively identify causal genes, with results available for public access.
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  • The study investigates the role of paused RNA polymerase II (Pol II) in gene regulation, particularly in the context of β-thalassemia and its effects on erythropoiesis (red blood cell formation).
  • Researchers found mutations in the SPT5 gene that disrupt the proper release of paused Pol II, leading to delays in the transition from progenitor to precursor cells in healthy human cells.
  • Despite these delays in gene expression and the cell cycle during differentiation, the cells eventually reach terminal differentiation, indicating that Pol II pausing plays a critical role in synchronizing the processes of proliferation and differentiation.
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  • Population isolates like Finland provide a unique advantage for genetic research by having concentrated deleterious alleles in low-frequency variants due to historical bottlenecks.
  • The FinnGen study aims to analyze data from 500,000 Finnish individuals, focusing on their genomes and health records, particularly as many participants are older and have disease-related data.
  • From the analysis of 224,737 participants and additional biobank data, researchers discovered 30 new associations and a total of 2,733 significant genetic links across various diseases, highlighting the importance of low-frequency variants in understanding common diseases.
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The discovery of genetic loci associated with complex diseases has outpaced the elucidation of mechanisms of disease pathogenesis. Here we conducted a genome-wide association study (GWAS) for coronary artery disease (CAD) comprising 181,522 cases among 1,165,690 participants of predominantly European ancestry. We detected 241 associations, including 30 new loci.

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Rare copy-number variants (rCNVs) include deletions and duplications that occur infrequently in the global human population and can confer substantial risk for disease. In this study, we aimed to quantify the properties of haploinsufficiency (i.e.

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Master regulators, such as the hematopoietic transcription factor (TF) GATA1, play an essential role in orchestrating lineage commitment and differentiation. However, the precise mechanisms by which such TFs regulate transcription through interactions with specific cis-regulatory elements remain incompletely understood. Here, we describe a form of congenital hemolytic anemia caused by missense mutations in an intrinsically disordered region of GATA1, with a poorly understood role in transcriptional regulation.

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  • 3' untranslated region (3'UTR) variants play a significant role in human traits and diseases, but identifying their causal relationships has been challenging.
  • Researchers developed a tool called the massively parallel reporter assay for 3'UTRs (MPRAu) to assess over 12,000 variants in human cell lines, enhancing our understanding of 3'UTR function and regulatory activity.
  • The study highlights potential causal variants linked to specific conditions, showcasing findings such as a variant that impacts a miRNA site influencing a viral defense gene and another that affects gene expression related to age-related macular degeneration.
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Genome-wide association studies (GWAS) have linked single nucleotide polymorphisms (SNPs) at >250 loci in the human genome to type 2 diabetes (T2D) risk. For each locus, identifying the functional variant(s) among multiple SNPs in high linkage disequilibrium is critical to understand molecular mechanisms underlying T2D genetic risk. Using massively parallel reporter assays (MPRA), we test the cis-regulatory effects of SNPs associated with T2D and altered in vivo islet chromatin accessibility in MIN6 β cells under steady state and pathophysiologic endoplasmic reticulum (ER) stress conditions.

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  • Effective interpretation of genome function now requires understanding the actual roles of cis-regulatory elements (CREs) beyond just mapping them.
  • We developed a new technique called HCR-FlowFISH that uses flow cytometry to assess the effects of CRISPR on these CREs by measuring native RNA levels.
  • In our study of over 325,000 genetic changes, we discovered that CREs can influence multiple genes simultaneously, bypass nearby genes, and exhibit both activation and silencing roles.
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  • Most variants found through Genome-Wide Association Studies (GWAS) are non-coding, prompting the need to study their regulatory functions more closely.
  • Traditional experimental methods to explore the impact of these variants on gene expression are limited in scale, lacking comprehensive high-throughput approaches.
  • The study introduces the expression modifier score (EMS) that utilizes a large dataset of causal variants to enhance predictions of how variants affect gene expression, leading to the identification of thousands of additional candidate regulatory variants and genes.
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  • Genome-wide association studies (GWAS) have found many noncoding regions related to diseases, but translating these findings into functional insights is challenging due to insufficient maps of enhancers and target genes.
  • The activity-by-contact (ABC) model was developed to predict enhancer-gene interactions and applied across 131 human cell types, linking over 5,000 GWAS signals to nearly 2,250 unique genes with implications for various diseases.
  • Specifically for inflammatory bowel disease (IBD), ABC model identified risk variants in enhancers that regulate gene expression, offering a new understanding of disease mechanisms and providing a blueprint for future connections between genetic variants and their functions.
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Admixed populations are routinely excluded from genomic studies due to concerns over population structure. Here, we present a statistical framework and software package, Tractor, to facilitate the inclusion of admixed individuals in association studies by leveraging local ancestry. We test Tractor with simulated and empirical two-way admixed African-European cohorts.

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Fine-mapping aims to identify causal variants impacting complex traits. We propose PolyFun, a computationally scalable framework to improve fine-mapping accuracy by leveraging functional annotations across the entire genome-not just genome-wide-significant loci-to specify prior probabilities for fine-mapping methods such as SuSiE or FINEMAP. In simulations, PolyFun + SuSiE and PolyFun + FINEMAP were well calibrated and identified >20% more variants with a posterior causal probability >0.

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