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1.
Cell Genom ; 4(5): 100556, 2024 May 08.
Artículo en Inglés | MEDLINE | ID: mdl-38697123

RESUMEN

The ch12q13 locus is among the most significant childhood obesity loci identified in genome-wide association studies. This locus resides in a non-coding region within FAIM2; thus, the underlying causal variant(s) presumably influence disease susceptibility via cis-regulation. We implicated rs7132908 as a putative causal variant by leveraging our in-house 3D genomic data and public domain datasets. Using a luciferase reporter assay, we observed allele-specific cis-regulatory activity of the immediate region harboring rs7132908. We generated isogenic human embryonic stem cell lines homozygous for either rs7132908 allele to assess changes in gene expression and chromatin accessibility throughout a differentiation to hypothalamic neurons, a key cell type known to regulate feeding behavior. The rs7132908 obesity risk allele influenced expression of FAIM2 and other genes and decreased the proportion of neurons produced by differentiation. We have functionally validated rs7132908 as a causal obesity variant that temporally regulates nearby effector genes and influences neurodevelopment and survival.


Asunto(s)
Regiones no Traducidas 3' , Obesidad Infantil , Humanos , Obesidad Infantil/genética , Regiones no Traducidas 3'/genética , Polimorfismo de Nucleótido Simple/genética , Cromosomas Humanos Par 12/genética , Niño , Neuronas/metabolismo , Estudio de Asociación del Genoma Completo , Alelos , Diferenciación Celular/genética , Predisposición Genética a la Enfermedad , Células Madre Embrionarias Humanas/metabolismo
2.
Sleep ; 2024 Apr 04.
Artículo en Inglés | MEDLINE | ID: mdl-38571402

RESUMEN

Although genome wide association studies (GWAS) have identified loci for sleep-related traits, they do not directly uncover the underlying causal variants and corresponding effector genes. The majority of such variants reside in non-coding regions and are therefore presumed to impact cis-regulatory elements. Our previously reported 'variant-to-gene mapping' effort in human induced pluripotent stem cell (iPSC)-derived neural progenitor cells (NPCs), combined with validation in both Drosophila and zebrafish, implicated PIG-Q as a functionally relevant gene at the insomnia 'WDR90' GWAS locus. However, importantly that effort did not characterize the corresponding underlying causal variant. Specifically, our previous 3D genomic datasets nominated a shortlist of three neighboring single nucleotide polymorphisms (SNPs) in strong linkage disequilibrium within an intronic enhancer region of WDR90 that contacted the open PIG-Q promoter. We sought to investigate the influence of these SNPs collectively and then individually on PIG-Q modulation to pinpoint the causal "regulatory" variant. Starting with gross level perturbation, deletion of the entire region in NPCs via CRISPR-Cas9 editing and subsequent RNA sequencing revealed expression changes in specific PIG-Q transcripts. Results from individual luciferase reporter assays for each SNP in iPSCs revealed that the region with the rs3752495 risk allele induced a ~2.5-fold increase in luciferase expression. Importantly, rs3752495 also exhibited an allele specific effect, with the risk allele increasing the luciferase expression by ~2-fold versus the non-risk allele. In conclusion, our variant-to-function approach and in vitro validation implicates rs3752495 as a causal insomnia variant embedded within WDR90 while modulating the expression of the distally located PIG-Q.

3.
medRxiv ; 2024 Mar 16.
Artículo en Inglés | MEDLINE | ID: mdl-38559031

RESUMEN

Genetic effects on changes in human traits over time are understudied and may have important pathophysiological impact. We propose a framework that enables data quality control, implements mixed models to evaluate trajectories of change in traits, and estimates phenotypes to identify age-varying genetic effects in genome-wide association studies (GWASs). Using childhood body mass index (BMI) as an example, we included 71,336 participants from six cohorts and estimated the slope and area under the BMI curve within four time periods (infancy, early childhood, late childhood and adolescence) for each participant, in addition to the age and BMI at the adiposity peak and the adiposity rebound. GWAS on each of the estimated phenotypes identified 28 genome-wide significant variants at 13 loci across the 12 estimated phenotypes, one of which was novel (in DAOA) and had not been previously associated with childhood or adult BMI. Genetic studies of changes in human traits over time could uncover novel biological mechanisms influencing quantitative traits.

4.
JBMR Plus ; 8(5): ziae051, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38686038

RESUMEN

Genome wide association study (GWAS)-implicated bone mineral density (BMD) signals have been shown to localize in cis-regulatory regions of distal effector genes using 3D genomic methods. Detailed characterization of such genes can reveal novel causal genes for BMD determination. Here, we elected to characterize the "DNM3" locus on chr1q24, where the long non-coding RNA DNM3OS and the embedded microRNA MIR199A2 (miR-199a-5p) are implicated as effector genes contacted by the region harboring variation in linkage disequilibrium with BMD-associated sentinel single nucleotide polymorphism, rs12041600. During osteoblast differentiation of human mesenchymal stem/progenitor cells (hMSC), miR-199a-5p expression was temporally decreased and correlated with the induction of osteoblastic transcription factors RUNX2 and Osterix. Functional relevance of miR-199a-5p downregulation in osteoblastogenesis was investigated by introducing miR-199a-5p mimic into hMSC. Cells overexpressing miR-199a-5p depicted a cobblestone-like morphological change and failed to produce BMP2-dependent extracellular matrix mineralization. Mechanistically, a miR-199a-5p mimic modified hMSC propagated normal SMAD1/5/9 signaling and expressed osteoblastic transcription factors RUNX2 and Osterix but depicted pronounced upregulation of SOX9 and enhanced expression of essential chondrogenic genes ACAN, COMP, and COL10A1. Mineralization defects, morphological changes, and enhanced chondrogenic gene expression associated with miR-199a-5p mimic over-expression were restored with miR-199a-5p inhibitor suggesting specificity of miR-199a-5p in chondrogenic fate specification. The expression of both the DNM3OS and miR-199a-5p temporally increased and correlated with hMSC chondrogenic differentiation. Although miR-199a-5p overexpression failed to further enhance chondrogenesis, blocking miR-199a-5p activity significantly reduced chondrogenic pellet size, extracellular matrix deposition, and chondrogenic gene expression. Taken together, our results indicate that oscillating miR-199a-5p levels dictate hMSC osteoblast or chondrocyte terminal fate. Our study highlights a functional role of miR-199a-5p as a BMD effector gene at the DNM3 BMD GWAS locus, where patients with cis-regulatory genetic variation which increases miR-199a-5p expression could lead to reduced osteoblast activity.

5.
bioRxiv ; 2024 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-38562830

RESUMEN

Over 1,100 independent signals have been identified with genome-wide association studies (GWAS) for bone mineral density (BMD), a key risk factor for mortality-increasing fragility fractures; however, the effector gene(s) for most remain unknown. Informed by a variant-to-gene mapping strategy implicating 89 non-coding elements predicted to regulate osteoblast gene expression at BMD GWAS loci, we executed a single-cell CRISPRi screen in human fetal osteoblast 1.19 cells (hFOBs). The BMD relevance of hFOBs was supported by heritability enrichment from cross-cell type stratified LD-score regression involving 98 cell types grouped into 15 tissues. 24 genes showed perturbation in the screen, with four (ARID5B, CC2D1B, EIF4G2, and NCOA3) exhibiting consistent effects upon siRNA knockdown on three measures of osteoblast maturation and mineralization. Lastly, additional heritability enrichments, genetic correlations, and multi-trait fine-mapping revealed that many BMD GWAS signals are pleiotropic and likely mediate their effects via non-bone tissues that warrant attention in future screens.

6.
Elife ; 122024 Apr 24.
Artículo en Inglés | MEDLINE | ID: mdl-38655862

RESUMEN

Ikaros is a transcriptional factor required for conventional T cell development, differentiation, and anergy. While the related factors Helios and Eos have defined roles in regulatory T cells (Treg), a role for Ikaros has not been established. To determine the function of Ikaros in the Treg lineage, we generated mice with Treg-specific deletion of the Ikaros gene (Ikzf1). We find that Ikaros cooperates with Foxp3 to establish a major portion of the Treg epigenome and transcriptome. Ikaros-deficient Treg exhibit Th1-like gene expression with abnormal production of IL-2, IFNg, TNFa, and factors involved in Wnt and Notch signaling. While Ikzf1-Treg-cko mice do not develop spontaneous autoimmunity, Ikaros-deficient Treg are unable to control conventional T cell-mediated immune pathology in response to TCR and inflammatory stimuli in models of IBD and organ transplantation. These studies establish Ikaros as a core factor required in Treg for tolerance and the control of inflammatory immune responses.


Asunto(s)
Factores de Transcripción Forkhead , Regulación de la Expresión Génica , Factor de Transcripción Ikaros , Linfocitos T Reguladores , Animales , Factor de Transcripción Ikaros/metabolismo , Factor de Transcripción Ikaros/genética , Linfocitos T Reguladores/inmunología , Linfocitos T Reguladores/metabolismo , Factores de Transcripción Forkhead/metabolismo , Factores de Transcripción Forkhead/genética , Ratones , Ratones Noqueados
7.
EBioMedicine ; 101: 105038, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38417377

RESUMEN

BACKGROUND: Carpal tunnel syndrome (CTS) is a common disorder caused by compression of the median nerve in the wrist, resulting in pain and numbness throughout the hand and forearm. While multiple behavioural and physiological factors influence CTS risk, a growing body of evidence supports a strong genetic contribution. Recent genome-wide association study (GWAS) efforts have reported 53 independent signals associated with CTS. While GWAS can identify genetic loci conferring risk, it does not determine which cell types drive the genetic aetiology of the trait, which variants are "causal" at a given signal, and which effector genes correspond to these non-coding variants. These obstacles limit interpretation of potential disease mechanisms. METHODS: We analysed CTS GWAS findings in the context of chromatin conformation between gene promoters and accessible chromatin regions across cellular models of bone, skeletal muscle, adipocytes and neurons. We identified proxy variants in high LD with the lead CTS sentinel SNPs residing in promoter connected open chromatin in the skeletal muscle and bone contexts. FINDINGS: We detected significant enrichment for heritability in skeletal muscle myotubes, as well as a weaker correlation in human mesenchymal stem cell-derived osteoblasts. In myotubes, our approach implicated 117 genes contacting 60 proxy variants corresponding to 20 of the 53 GWAS signals. In the osteoblast context we implicated 30 genes contacting 24 proxy variants coinciding with 12 signals, of which 19 genes shared. We subsequently prioritized BZW2 as a candidate effector gene in CTS and implicated it as novel gene that perturbs myocyte differentiation in vitro. INTERPRETATION: Taken together our results suggest that the CTS genetic component influences the size, integrity, and organization of multiple tissues surrounding the carpal tunnel, in particular muscle and bone, to predispose the nerve to being compressed in this disease setting. FUNDING: This work was supported by NIH Grant UM1 DK126194 (SFAG and WY), R01AG072705 (SFAG & KDH) and the Center for Spatial and Functional Genomics at CHOP (SFAG & ADW). SFAG is supported by the Daniel B. Burke Endowed Chair for Diabetes Research. WY is supported by the Perelman School of Medicine of the University of Pennsylvania.


Asunto(s)
Síndrome del Túnel Carpiano , Humanos , Síndrome del Túnel Carpiano/genética , Estudio de Asociación del Genoma Completo , Músculo Esquelético , Mapeo Cromosómico , Cromatina/genética , Proteínas de Unión al ADN/genética
8.
Nat Metab ; 6(1): 12-13, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38253930

Asunto(s)
Leche , Animales , Heces
9.
medRxiv ; 2024 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-37693606

RESUMEN

The prevalence of childhood obesity is increasing worldwide, along with the associated common comorbidities of type 2 diabetes and cardiovascular disease in later life. Motivated by evidence for a strong genetic component, our prior genome-wide association study (GWAS) efforts for childhood obesity revealed 19 independent signals for the trait; however, the mechanism of action of these loci remains to be elucidated. To molecularly characterize these childhood obesity loci we sought to determine the underlying causal variants and the corresponding effector genes within diverse cellular contexts. Integrating childhood obesity GWAS summary statistics with our existing 3D genomic datasets for 57 human cell types, consisting of high-resolution promoter-focused Capture-C/Hi-C, ATAC-seq, and RNA-seq, we applied stratified LD score regression and calculated the proportion of genome-wide SNP heritability attributable to cell type-specific features, revealing pancreatic alpha cell enrichment as the most statistically significant. Subsequent chromatin contact-based fine-mapping was carried out for genome-wide significant childhood obesity loci and their linkage disequilibrium proxies to implicate effector genes, yielded the most abundant number of candidate variants and target genes at the BDNF, ADCY3, TMEM18 and FTO loci in skeletal muscle myotubes and the pancreatic beta-cell line, EndoC-BH1. One novel implicated effector gene, ALKAL2 - an inflammation-responsive gene in nerve nociceptors - was observed at the key TMEM18 locus across multiple immune cell types. Interestingly, this observation was also supported through colocalization analysis using expression quantitative trait loci (eQTL) derived from the Genotype-Tissue Expression (GTEx) dataset, supporting an inflammatory and neurologic component to the pathogenesis of childhood obesity. Our comprehensive appraisal of 3D genomic datasets generated in a myriad of different cell types provides genomic insights into pediatric obesity pathogenesis.

10.
bioRxiv ; 2023 Aug 22.
Artículo en Inglés | MEDLINE | ID: mdl-37662342

RESUMEN

The ch12q13 obesity locus is among the most significant childhood obesity loci identified in genome-wide association studies. This locus resides in a non-coding region within FAIM2; thus, the underlying causal variant(s) presumably influence disease susceptibility via an influence on cis-regulation within the genomic region. We implicated rs7132908 as a putative causal variant at this locus leveraging a combination of our inhouse 3D genomic data, public domain datasets, and several computational approaches. Using a luciferase reporter assay in human primary astrocytes, we observed allele-specific cis-regulatory activity of the immediate region harboring rs7132908. Motivated by this finding, we went on to generate isogenic human embryonic stem cell lines homozygous for either rs7132908 allele with CRISPR-Cas9 homology-directed repair to assess changes in gene expression due to genotype and chromatin accessibility throughout a differentiation to hypothalamic neurons, a key cell type known to regulate feeding behavior. We observed that the rs7132908 obesity risk allele influenced the expression of FAIM2 along with other genes, decreased the proportion of neurons produced during differentiation, up-regulated cell death gene sets, and conversely down-regulated neuron differentiation gene sets. We have therefore functionally validated rs7132908 as a causal obesity variant which temporally regulates nearby effector genes at the ch12q13 locus and influences neurodevelopment and survival.

11.
Gastro Hep Adv ; 2(6): 830-842, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37736163

RESUMEN

BACKGROUND AND AIMS: A key histopathological feature of inflammatory bowel disease is damage to the mucosa, including breakdown of the epithelial barrier. Human enteroids and colonoids are a critical bench-to-bedside tool for studying the epithelium in inflammatory bowel disease. The goal of the current study was to define transcriptional differences in healthy versus diseased subjects that are sustained in enteroids and colonoids, including from disease-spared tissue. METHODS: Biopsies and matching enteroid or colonoid cultures from pediatric patients with ileal Crohn disease (N = 6) and control subjects (N = 17) were subjected to RNA sequencing followed by bioinformatic and machine learning analyses. Late passage enteroids were exposed to cytokines to assess durable transcriptional differences. RESULTS: We observed substantial overlap of pathways upregulated in Crohn disease in enteroids and ileal biopsies, as well as colonoids and rectal biopsies. KEGG pathways for cytokine-cytokine receptor interaction, chemokine signaling, protein export, and Toll-like receptor signaling were upregulated in both ileal and rectal biopsies, as well as enteroids and colonoids. In vitro cytokine exposure reactivated genes previously increased in biopsies. Machine learning predicted biopsy location (100% accuracy) and donor disease status (83% accuracy). A random forest classifier generated using ileal enteroids identified rectal colonoids from ileal Crohn disease subjects with 80% accuracy. CONCLUSION: We confirmed transcriptional profiles of Crohn disease biopsies are expressed in enteroids and colonoids. Furthermore, transcriptomic data from disease-spared rectal tissue can identify patients with ileal Crohn disease. Our data support the use of patient enteroids and colonoids as critical translational tools for the study of inflammatory bowel disease.

12.
Nat Commun ; 14(1): 5562, 2023 09 09.
Artículo en Inglés | MEDLINE | ID: mdl-37689782

RESUMEN

Genes act in concert with each other in specific contexts to perform their functions. Determining how these genes influence complex traits requires a mechanistic understanding of expression regulation across different conditions. It has been shown that this insight is critical for developing new therapies. Transcriptome-wide association studies have helped uncover the role of individual genes in disease-relevant mechanisms. However, modern models of the architecture of complex traits predict that gene-gene interactions play a crucial role in disease origin and progression. Here we introduce PhenoPLIER, a computational approach that maps gene-trait associations and pharmacological perturbation data into a common latent representation for a joint analysis. This representation is based on modules of genes with similar expression patterns across the same conditions. We observe that diseases are significantly associated with gene modules expressed in relevant cell types, and our approach is accurate in predicting known drug-disease pairs and inferring mechanisms of action. Furthermore, using a CRISPR screen to analyze lipid regulation, we find that functionally important players lack associations but are prioritized in trait-associated modules by PhenoPLIER. By incorporating groups of co-expressed genes, PhenoPLIER can contextualize genetic associations and reveal potential targets missed by single-gene strategies.


Asunto(s)
Repeticiones Palindrómicas Cortas Agrupadas y Regularmente Espaciadas , Epistasis Genética , Causalidad , Redes Reguladoras de Genes , Transcriptoma
13.
Am J Clin Nutr ; 118(4): 792-803, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37598746

RESUMEN

BACKGROUND: Body composition assessment aids evaluation of energy stores and the impact of diseases and interventions on child growth. Current United States pediatric reference ranges from the National Health and Nutrition Examination Survey (NHANES) include 20% of children with obesity, body mass index of ≥95th percentile. OBJECTIVES: This study aimed to develop dual energy X-ray absorptiometry (DXA) based reference ranges in a diverse cohort with low-obesity prevalence from the Bone Mineral Density in Childhood Study (BMDCS). METHODS: This is a secondary analysis of a longitudinal, prospective, observational cohort. Healthy children (height and BMI within 3rd to 97th percentiles, ages 5-19 y at enrollment), from 5 United States centers were measured annually for ≤7 visits. Whole body scans were acquired using Hologic scanners. A subsample underwent repeat measurements to determine precision. We generated reference ranges for appendicular and total lean soft tissue mass index (LSTM Index), fat mass index (FMI), and other body composition measures. Resulting curves were compared to NHANES and across subgroups. Sex and age-specific equations were developed to adjust body composition Z-scores for height Z score. RESULTS: We obtained 9846 scans of 2011 participants (51% female, 22% Black, 17% Hispanic, 48% White, 7% Asian/Pacific Islander, and 6% with obesity). Precision (percent coefficient of variation) ranged from 0.7% to 1.96%. Median and-2 standard deviation curves for BMDCS and NHANES were similar, but NHANES +2 standard deviation LSTM Index and FMI curves were distinctly greater than the respective BMDCS curves. Subgroup differences were more extreme for appendicular LSTM Index-Z (mean ± SD: Asian -0.52 ± 0.93 compared with Black 0.77 ± 0.87) than for FMI-Z (Hispanic 0.29 ± 0.98 compared with Black -0.14 ± 1.1) and were smaller for Z-scores adjusted for height Z-score. CONCLUSIONS: These reference ranges add to sparse normative data regarding body composition in children and adolescents and are based on a cohort with an obesity prevalence similar to current BMI charts. Awareness of subgroup differences aids in interpreting results.


Asunto(s)
Composición Corporal , Densidad Ósea , Adolescente , Humanos , Femenino , Niño , Estados Unidos/epidemiología , Masculino , Absorciometría de Fotón/métodos , Encuestas Nutricionales , Valores de Referencia , Estudios Prospectivos , Obesidad/epidemiología , Índice de Masa Corporal
14.
Commun Biol ; 6(1): 852, 2023 08 16.
Artículo en Inglés | MEDLINE | ID: mdl-37587153

RESUMEN

Omega-3 (n-3) and omega-6 (n-6) polyunsaturated fatty acids (PUFAs) play critical roles in human health. Prior genome-wide association studies (GWAS) of n-3 and n-6 PUFAs in European Americans from the CHARGE Consortium have documented strong genetic signals in/near the FADS locus on chromosome 11. We performed a GWAS of four n-3 and four n-6 PUFAs in Hispanic American (n = 1454) and African American (n = 2278) participants from three CHARGE cohorts. Applying a genome-wide significance threshold of P < 5 × 10-8, we confirmed association of the FADS signal and found evidence of two additional signals (in DAGLA and BEST1) within 200 kb of the originally reported FADS signal. Outside of the FADS region, we identified novel signals for arachidonic acid (AA) in Hispanic Americans located in/near genes including TMX2, SLC29A2, ANKRD13D and POLD4, and spanning a > 9 Mb region on chromosome 11 (57.5 Mb ~ 67.1 Mb). Among these novel signals, we found associations unique to Hispanic Americans, including rs28364240, a POLD4 missense variant for AA that is common in CHARGE Hispanic Americans but absent in other race/ancestry groups. Our study sheds light on the genetics of PUFAs and the value of investigating complex trait genetics across diverse ancestry populations.


Asunto(s)
Ácidos Grasos Omega-6 , Estudio de Asociación del Genoma Completo , Humanos , Negro o Afroamericano/genética , Genómica , Hispánicos o Latinos/genética , Bestrofinas
15.
Diabetes ; 72(9): 1184-1186, 2023 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-37603723

Asunto(s)
Mutación
16.
Cancer Res ; 83(20): 3462-3477, 2023 10 13.
Artículo en Inglés | MEDLINE | ID: mdl-37584517

RESUMEN

Long noncoding RNAs (lncRNA) play an important role in gene regulation and contribute to tumorigenesis. While pan-cancer studies of lncRNA expression have been performed for adult malignancies, the lncRNA landscape across pediatric cancers remains largely uncharted. Here, we curated RNA sequencing data for 1,044 pediatric leukemia and extracranial solid tumors and integrated paired tumor whole genome sequencing and epigenetic data in relevant cell line models to explore lncRNA expression, regulation, and association with cancer. A total of 2,657 lncRNAs were robustly expressed across six pediatric cancers, including 1,142 exhibiting histotype-elevated expression. DNA copy number alterations contributed to lncRNA dysregulation at a proportion comparable to protein coding genes. Application of a multidimensional framework to identify and prioritize lncRNAs impacting gene networks revealed that lncRNAs dysregulated in pediatric cancer are associated with proliferation, metabolism, and DNA damage hallmarks. Analysis of upstream regulation via cell type-specific transcription factors further implicated distinct histotype-elevated and developmental lncRNAs. Integration of these analyses prioritized lncRNAs for experimental validation, and silencing of TBX2-AS1, the top-prioritized neuroblastoma-specific lncRNA, resulted in significant growth inhibition of neuroblastoma cells, confirming the computational predictions. Taken together, these data provide a comprehensive characterization of lncRNA regulation and function in pediatric cancers and pave the way for future mechanistic studies. SIGNIFICANCE: Comprehensive characterization of lncRNAs in pediatric cancer leads to the identification of highly expressed lncRNAs across childhood cancers, annotation of lncRNAs showing histotype-specific elevated expression, and prediction of lncRNA gene regulatory networks.


Asunto(s)
Leucemia , Neuroblastoma , ARN Largo no Codificante , Adulto , Humanos , Niño , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , Perfilación de la Expresión Génica , Neuroblastoma/genética , Leucemia/genética , Genómica , Redes Reguladoras de Genes , Regulación Neoplásica de la Expresión Génica
17.
Commun Biol ; 6(1): 691, 2023 07 04.
Artículo en Inglés | MEDLINE | ID: mdl-37402774

RESUMEN

Skull bone mineral density (SK-BMD) provides a suitable trait for the discovery of key genes in bone biology, particularly to intramembranous ossification, not captured at other skeletal sites. We perform a genome-wide association meta-analysis (n ~ 43,800) of SK-BMD, identifying 59 loci, collectively explaining 12.5% of the trait variance. Association signals cluster within gene-sets involved in skeletal development and osteoporosis. Among the four novel loci (ZIC1, PRKAR1A, AZIN1/ATP6V1C1, GLRX3), there are factors implicated in intramembranous ossification and as we show, inherent to craniosynostosis processes. Functional follow-up in zebrafish confirms the importance of ZIC1 on cranial suture patterning. Likewise, we observe abnormal cranial bone initiation that culminates in ectopic sutures and reduced BMD in mosaic atp6v1c1 knockouts. Mosaic prkar1a knockouts present asymmetric bone growth and, conversely, elevated BMD. In light of this evidence linking SK-BMD loci to craniofacial abnormalities, our study provides new insight into the pathophysiology, diagnosis and treatment of skeletal diseases.


Asunto(s)
Densidad Ósea , Craneosinostosis , Animales , Densidad Ósea/genética , Estudio de Asociación del Genoma Completo , Pez Cebra/genética , Cráneo , Craneosinostosis/genética , Factores de Transcripción/genética
18.
medRxiv ; 2023 Jun 29.
Artículo en Inglés | MEDLINE | ID: mdl-37425708

RESUMEN

Genome-wide association studies (GWAS) have underrepresented individuals from non-European populations, impeding progress in characterizing the genetic architecture and consequences of health and disease traits. To address this, we present a population-stratified phenome-wide GWAS followed by a multi-population meta-analysis for 2,068 traits derived from electronic health records of 635,969 participants in the Million Veteran Program (MVP), a longitudinal cohort study of diverse U.S. Veterans genetically similar to the respective African (121,177), Admixed American (59,048), East Asian (6,702), and European (449,042) superpopulations defined by the 1000 Genomes Project. We identified 38,270 independent variants associating with one or more traits at experiment-wide P<4.6×10-11 significance; fine-mapping 6,318 signals identified from 613 traits to single-variant resolution. Among these, a third (2,069) of the associations were found only among participants genetically similar to non-European reference populations, demonstrating the importance of expanding diversity in genetic studies. Our work provides a comprehensive atlas of phenome-wide genetic associations for future studies dissecting the architecture of complex traits in diverse populations.

19.
Diabetologia ; 66(9): 1589-1600, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37439792

RESUMEN

Iterative advances in understanding of the genetics of type 1 diabetes have identified >70 genetic regions associated with risk of the disease, including strong associations across the HLA class II region that account for >50% of heritability. The increased availability of genetic data combined with the decreased costs of generating these data, have facilitated the development of polygenic scores that aggregate risk variants from associated loci into a single number: either a genetic risk score (GRS) or a polygenic risk score (PRS). PRSs incorporate the risk of many possibly correlated variants from across the genome, even if they do not reach genome-wide significance, whereas GRSs estimate the cumulative contribution of a smaller subset of genetic variants that reach genome-wide significance. Type 1 diabetes GRSs have utility in diabetes classification, aiding discrimination between type 1 diabetes, type 2 diabetes and MODY. Type 1 diabetes GRSs are also being used in newborn screening studies to identify infants at risk of future presentation of the disease. Most early studies of type 1 diabetes genetics have been conducted in European ancestry populations, but, to develop accurate GRSs across diverse ancestries, large case-control cohorts from non-European populations are still needed. The current barriers to GRS implementation within healthcare are mainly related to a lack of guidance and knowledge on integration with other biomarkers and clinical variables. Once these limitations are addressed, there is huge potential for 'test and treat' approaches to be used to tailor care for individuals with type 1 diabetes.


Asunto(s)
Diabetes Mellitus Tipo 1 , Diabetes Mellitus Tipo 2 , Recién Nacido , Humanos , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/diagnóstico , Predisposición Genética a la Enfermedad/genética , Factores de Riesgo , Biomarcadores , Estudio de Asociación del Genoma Completo
20.
Neurobiol Sleep Circadian Rhythms ; 14: 100096, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-37287661

RESUMEN

Sleep fulfills critical functions in neurodevelopment, such as promoting synaptic plasticity, neuronal wiring, and brain connectivity which are critical phenomena in Autism Spectrum Disorder (ASD) pathophysiology. Sleep disturbance, specifically insomnia, accompanies ASD and is associated with more severe core symptoms (e.g., social impairment). It is possible that focusing on identifying effective ways to treat sleep problems can help alleviate other ASD-related symptoms. A body of evidence indicates shared mechanisms and neurobiological substrates between sleep and ASD and investigation of these may inform therapeutic effects of improving sleep at both behavioral and molecular levels. In this study, we tested if sleep and social behavior were different in a zebrafish model with the arid1b gene mutated compared to controls. This gene was selected for study as expert curations conducted for the Simons Foundation for Autism Research Institute (SFARI) Gene database define it is as a 'high confidence' ASD gene (i.e., clearly implicated) encoding a chromatin remodeling protein. Homozygous arid1b mutants displayed increased arousability and light sleep compared to their heterozygous and wild type counterparts, based on testing a mechano-acoustic stimulus presenting different vibration frequencies of increasing intensity to detect sleep depth. In addition, decreased social preference was observed in arid1b heterozygous and homozygous mutant zebrafish. The behavioral phenotypes reported in our study are in line with findings from mouse models and human studies and demonstrate the utility of zebrafish as a vertebrate model system with high throughput phenotyping in the investigation of changes in sleep in models relevant to ASD. Furthermore, we demonstrate the importance of including assessments of arousal threshold when studying sleep using in vivo models.

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