Phenome-wide association study of monogenic inflammatory bowel disease genes in diverse biobanks identifies population-specific and shared Goldilocks alleles: implications for Precision Medicine.

Background And Aims: Monogenic forms of inflammatory bowel disease (IBD) are driven by variants in genes critical to pathways in intestinal homeostasis and immunity. We investigated gene- and variant-level effects of these genes with IBD and phenome-wide association, leveraging large-scale whole exome sequencing data across 4 diverse cohorts: BioMe Biobank (Regeneron and Sema4), Penn Med Biobank, and UK Biobank.

Methods: Predicted loss- and gain-of function variants were extracted from 102 monogenic genes.

Age-related patterns of microbial dysbiosis in multiplex inflammatory bowel disease families.

Objective: IBD is characterised by dysbiosis, but it remains unclear to what extent dysbiosis develops in unaffected at-risk individuals. To address this, we investigated age-related patterns of faecal and serum markers of dysbiosis in high-risk multiplex IBD families (two or more affected first-degree relatives).

Design: Faecal and serum samples were collected from multiplex IBD and control families (95 IBD, 292 unaffected, 51 controls).

After Surgically Induced Remission, Ileal and Colonic Mucosa-Associated Microbiota Predicts Crohn's Disease Recurrence.

Background & Aims: Investigating the tissue-associated microbiota after surgically induced remission may help to understand the mechanisms initiating intestinal inflammation in Crohn's disease.

Methods: Patients with Crohn's disease undergoing ileocolic resection were prospectively recruited in 6 academic centers. Biopsy samples from the neoterminal ileum, colon, and rectosigmoid were obtained from colonoscopies performed after surgery.

Multimodal single-cell analyses reveal mechanisms of perianal fistula in diverse patients with Crohn's disease.

Background: Crohn's disease complicated by perianal fistulae is more prevalent and severe in patients of African ancestry.

Methods: We profiled single cells from diverse patients with Crohn's disease with perianal fistula from colorectal mucosa and fistulous tracts. Immunofluorescence was performed to validate predicted cell-cell interactions.

Identifying high-impact variants and genes in exomes of Ashkenazi Jewish inflammatory bowel disease patients.

Inflammatory bowel disease (IBD) is a group of chronic digestive tract inflammatory conditions whose genetic etiology is still poorly understood. The incidence of IBD is particularly high among Ashkenazi Jews. Here, we identify 8 novel and plausible IBD-causing genes from the exomes of 4453 genetically identified Ashkenazi Jewish IBD cases (1734) and controls (2719).

NOX1 is essential for TNFα-induced intestinal epithelial ROS secretion and inhibits M cell signatures.

Objective: Loss-of-function mutations in genes generating reactive oxygen species (ROS), such as , are associated with IBD. Mechanisms whereby loss of ROS drive IBD are incompletely defined.

Design: ROS measurements and single-cell transcriptomics were performed on colonoids stratified by genotype and TNFα stimulation.

Large-scale sequencing identifies multiple genes and rare variants associated with Crohn's disease susceptibility.

Genome-wide association studies (GWASs) have identified hundreds of loci associated with Crohn's disease (CD). However, as with all complex diseases, robust identification of the genes dysregulated by noncoding variants typically driving GWAS discoveries has been challenging. Here, to complement GWASs and better define actionable biological targets, we analyzed sequence data from more than 30,000 patients with CD and 80,000 population controls.

Utility of polygenic embryo screening for disease depends on the selection strategy.

Polygenic risk scores (PRSs) have been offered since 2019 to screen in vitro fertilization embryos for genetic liability to adult diseases, despite a lack of comprehensive modeling of expected outcomes. Here we predict, based on the liability threshold model, the expected reduction in complex disease risk following for a single disease. A strong determinant of the potential utility of such screening is the , a factor that has not been previously studied.

Stratification of risk of progression to colectomy in ulcerative colitis via measured and predicted gene expression.

An important goal of clinical genomics is to be able to estimate the risk of adverse disease outcomes. Between 5% and 10% of individuals with ulcerative colitis (UC) require colectomy within 5 years of diagnosis, but polygenic risk scores (PRSs) utilizing findings from genome-wide association studies (GWASs) are unable to provide meaningful prediction of this adverse status. By contrast, in Crohn disease, gene expression profiling of GWAS-significant genes does provide some stratification of risk of progression to complicated disease in the form of a transcriptional risk score (TRS).

A myeloid-stromal niche and gp130 rescue in NOD2-driven Crohn's disease.

Crohn's disease is a chronic inflammatory intestinal disease that is frequently accompanied by aberrant healing and stricturing complications. Crosstalk between activated myeloid and stromal cells is critical in the pathogenicity of Crohn's disease, and increases in intravasating monocytes are correlated with a lack of response to anti-TNF treatment. The risk alleles with the highest effect on Crohn's disease are loss-of-function mutations in NOD2, which increase the risk of stricturing.

Inflamed Ulcerative Colitis Regions Associated With MRGPRX2-Mediated Mast Cell Degranulation and Cell Activation Modules, Defining a New Therapeutic Target.

Background & Aims: Recent literature has implicated a key role for mast cells in murine models of colonic inflammation, but their role in human ulcerative colitis (UC) is not well established. A major advance has been the identification of mrgprb2 (human orthologue, MRGPX2) as mediating IgE-independent mast cell activation. We sought to define mechanisms of mast cell activation and MRGPRX2 in human UC.

Common and Rare Variant Prediction and Penetrance of IBD in a Large, Multi-ethnic, Health System-based Biobank Cohort.

Background And Aims: Polygenic risk scores (PRS) may soon be used to predict inflammatory bowel disease (IBD) risk in prevention efforts. We leveraged exome-sequence and single nucleotide polymorphism (SNP) array data from 29,358 individuals in the multiethnic, randomly ascertained health system-based BioMe biobank to define effects of common and rare IBD variants on disease prediction and pathophysiology.

Methods: PRS were calculated from European, African American, and Ashkenazi Jewish (AJ) reference case-control studies, and a meta-GWAS run using all three association datasets.

Single-Cell Analysis of Crohn's Disease Lesions Identifies a Pathogenic Cellular Module Associated with Resistance to Anti-TNF Therapy.

Clinical benefits of cytokine blockade in ileal Crohn's disease (iCD) are limited to a subset of patients. Here, we applied single-cell technologies to iCD lesions to address whether cellular heterogeneity contributes to treatment resistance. We found that a subset of patients expressed a unique cellular module in inflamed tissues that consisted of IgG plasma cells, inflammatory mononuclear phagocytes, activated T cells, and stromal cells, which we named the GIMATS module.

Prioritizing Crohn's disease genes by integrating association signals with gene expression implicates monocyte subsets.

Genome-wide association studies have identified ~170 loci associated with Crohn's disease (CD) and defining which genes drive these association signals is a major challenge. The primary aim of this study was to define which CD locus genes are most likely to be disease related. We developed a gene prioritization regression model (GPRM) by integrating complementary mRNA expression datasets, including bulk RNA-Seq from the terminal ileum of 302 newly diagnosed, untreated CD patients and controls, and in stimulated monocytes.

Functional variants in the gene confer shared effects on risk for Crohn's disease and Parkinson's disease.

Crohn's disease (CD), a form of inflammatory bowel disease, has a higher prevalence in Ashkenazi Jewish than in non-Jewish European populations. To define the role of nonsynonymous mutations, we performed exome sequencing of Ashkenazi Jewish patients with CD, followed by array-based genotyping and association analysis in 2066 CD cases and 3633 healthy controls. We detected association signals in the gene that conferred risk for CD (N2081D variant, = 9.

Different tissue phagocytes sample apoptotic cells to direct distinct homeostasis programs.

Recognition and removal of apoptotic cells by professional phagocytes, including dendritic cells and macrophages, preserves immune self-tolerance and prevents chronic inflammation and autoimmune pathologies. The diverse array of phagocytes that reside within different tissues, combined with the necessarily prompt nature of apoptotic cell clearance, makes it difficult to study this process in situ. The full spectrum of functions executed by tissue-resident phagocytes in response to homeostatic apoptosis, therefore, remains unclear.

Escape to Ferality: The Endoferal Origin of Weedy Rice from Crop Rice through De-Domestication.

Domestication is the hallmark of evolution and civilization and harnesses biodiversity through selection for specific traits. In regions where domesticated lines are grown near wild relatives, congeneric sources of aggressive weedy genotypes cause major economic losses. Thus, the origins of weedy genotypes where no congeneric species occur raise questions regarding management effectiveness and evolutionary mechanisms responsible for weedy population success.

Improved integrative framework combining association data with gene expression features to prioritize Crohn's disease genes.

Genome-wide association studies in Crohn's disease (CD) have identified 140 genome-wide significant loci. However, identification of genes driving association signals remains challenging. Furthermore, genome-wide significant thresholds limit false positives at the expense of decreased sensitivity.