scholarly journals Fine-mapping the MHC locus in juvenile idiopathic arthritis (JIA) reveals genetic heterogeneity corresponding to distinct adult inflammatory arthritic diseases

2016 ◽  
Vol 76 (4) ◽  
pp. 765-772 ◽  
Author(s):  
A Hinks ◽  
J Bowes ◽  
J Cobb ◽  
H C Ainsworth ◽  
M C Marion ◽  
...  
Keyword(s):  
Juvenile Idiopathic Arthritis ◽  
Fine Mapping ◽  
Genetic Data ◽  
Shared Knowledge ◽  
Bivariate Analysis ◽  
Nucleotide Polymorphisms ◽  
Single Nucleotide ◽  
Mhc Locus ◽  
First Time ◽  
Current Classification System

ObjectivesJuvenile idiopathic arthritis (JIA) is a heterogeneous group of diseases, comprising seven categories. Genetic data could potentially be used to help redefine JIA categories and improve the current classification system. The human leucocyte antigen (HLA) region is strongly associated with JIA. Fine-mapping of the region was performed to look for similarities and differences in HLA associations between the JIA categories and define correspondences with adult inflammatory arthritides.MethodsDense genotype data from the HLA region, from the Immunochip array for 5043 JIA cases and 14 390 controls, were used to impute single-nucleotide polymorphisms, HLA classical alleles and amino acids. Bivariate analysis was performed to investigate genetic correlation between the JIA categories. Conditional analysis was used to identify additional effects within the region. Comparison of the findings with those in adult inflammatory arthritic diseases was performed.ResultsWe identified category-specific associations and have demonstrated for the first time that rheumatoid factor (RF)-negative polyarticular JIA and oligoarticular JIA are genetically similar in their HLA associations. We also observe that each JIA category potentially has an adult counterpart. The RF-positive polyarthritis association at HLA-DRB1 amino acid at position 13 mirrors the association in adult seropositive rheumatoid arthritis (RA). Interestingly, the combined oligoarthritis and RF-negative polyarthritis dataset shares the same association with adult seronegative RA.ConclusionsThe findings suggest the value of using genetic data in helping to classify the categories of this heterogeneous disease. Mapping JIA categories to adult counterparts could enable shared knowledge of disease pathogenesis and aetiology and facilitate transition from paediatric to adult services.

EPCO-02. GERMLINE SINGLE NUCLEOTIDE POLYMORPHISM rs55705857 AT 8q24 INTERACTS WITH SOMATIC IDH1 MUTATION TO ENHANCE HUMAN GLIOMA FORMATION

2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi1-vi1
Author(s):  
Kristen Drucker ◽  
Connor Yanchus ◽  
Thomas Kollmeyer ◽  
Asma Ali ◽  
Decker Paul ◽  
...  
Keyword(s):  
Fine Mapping ◽  
Dna Interaction ◽  
Genomic Region ◽  
Idh1 Mutation ◽  
Normal Brain ◽  
Nucleotide Polymorphisms ◽  
Human Glioma ◽  
Single Nucleotide ◽  
Coding Regions ◽  
Chromatin Immunoprecipitation Sequencing

Abstract BACKGROUND Determination of the causation of germline single nucleotide polymorphisms (SNPs) located in non-coding regions of the genome is challenging. The genomic region of 8q24 has been identified as important in many kinds of cancer, linked to a topologically associated domain (TAD) encompassing MYC; this TAD contains a GWAS SNP (rs55705857) associated with IDH-mutant glioma. METHODS Germline genotyping data from 622 IDH-mutant glioma and 668 controls were used to fine map the rs55705857 locus by detailed haplotype analysis. Chromatin immunoprecipitation sequencing (ChIP-seq) of histone markers H3K4me1, H3K4me3, H3K27ac and H3K36me3 was performed on normal brain samples (n=8) and human glioma samples (n=11 IDH-wt and 52 IDH-mut). RNAseq from 9 normal and 83 brain tumors (n=26 IDH-wt and 55 IDH-mut) were used to assess differential gene expression. RESULTS Fine-mapping identified rs55705857 SNP as the most likely causative allele (OR=8.69; p<0.001) within 8q24 for the development of IDH-mutant glioma. At rs55705857, both H3K27ac and H3K4me1 in IDH-mutant vs IDH-wt tumors were increased 3.05- and 1.58-fold, respectively (DiffBind; p=5.81×10-7 and p=2.31×10-3). ChromHMM analysis of the marks indicated that promoter and enhancer functions were significantly increased, and the activity broadened at rs55705857 in IDH-mut gliomas compared to IDH-wt tumors and normal brain samples. This enhancement correlated with significant increased MYC expression in IDH-mut gliomas (p=3.1×10-13), as well as alterations of Myc signaling targets. Publicly available ATACseq, ChIPseq and long-range DNA interaction data demonstrated that the rs55705857 locus is open and interacts with the MYC promoter. CONCLUSIONS Fine-mapping of the 8q24 locus provided strong evidence that rs55705857 is the causative 8q24 locus associated with IDH-mut glioma. Functional experiments suggest that IDH mutation facilitates rs55705857 interaction with MYC to alter downstream MYC targets.

scholarly journals TNF-αPolymorphisms in Juvenile Idiopathic Arthritis: Which Potential Clinical Implications?

2012 ◽  
Vol 2012 ◽  
pp. 1-16 ◽  
Author(s):  
A. Scardapane ◽  
L. Breda ◽  
M. Lucantoni ◽  
F. Chiarelli
Keyword(s):  
Juvenile Idiopathic Arthritis ◽  
Large Scale ◽  
Nucleotide Polymorphisms ◽  
Necrosis Factor Alpha ◽  
Single Nucleotide ◽  
Adult Rheumatoid Arthritis ◽  
Functional Consequences ◽  
Factor Alpha ◽  
Necrosis Factor ◽  
Important Cytokine

Whether tumor necrosis factor alpha (TNF-α) gene polymorphisms (SNPs) influence disease susceptibility and treatment of patients with juvenile idiopathic arthritis (JIA) is presently uncertain. TNF-αis one of the most important cytokine involved in JIA pathogenesis. Several single nucleotide polymorphisms (SNPs) have been identified within the region of the TNF-αgene but only a very small minority have proven functional consequences and have been associated with susceptibility to JIA. An association between some TNF-αSNPs and adult rheumatoid arthritis (RA) susceptibility, severity and clinical response to anti-TNF-αtreatment has been reported. The most frenquetly studied TNF-αSNP is located at −308 position, where a substitution of the G allele with the rare A allele has been found. The presence of the allele −308A is associated to JIA and to a poor prognosis. Besides, the −308G genotype has been associated with a better response to anti-TNF-αtherapy in JIA patients, confirming adult data. Psoriatic and oligoarticular arthritis are significantly associated to the −238 SNP only in some works. Studies considering other SNPs are conflicting and inconclusive. Large scale studies are required to define the contribution of TNF-αgene products to disease pathogenesis and anti-TNF-αtherapeutic efficacy in JIA.

scholarly journals Heterozygous Ile453Val codon mutation in exon 7, homozygous single nucleotide polymorphisms in intron 2 and 5 of cathepsin C are associated with Haim-Munk syndrome

2014 ◽  
Vol 08 (01) ◽  
pp. 079-084 ◽  
Author(s):  
Nalini Aswath ◽  
Bhuminathan Swamikannu ◽  
Sankar Narayanan Ramakrishnan ◽  
Rajendran Shanmugam ◽  
Jayakar Thomas ◽  
...  
Keyword(s):  
Single Nucleotide Polymorphisms ◽  
Direct Sequencing ◽  
Sequencing Analysis ◽  
Nucleotide Polymorphisms ◽  
Single Nucleotide ◽  
Heterozygous Condition ◽  
South Indian ◽  
The Subject ◽  
First Time ◽  
Intron 2

ABSTRACT Objective: In the present study, we have investigated the genetic status of CTSC gene in a HMS subject, who along with her parents belonged to non-Jewish South Indian Dravidian community. Materials and Methods: Genomic deoxyribonucleic acid isolated from the peripheral blood of the subject was amplified with CTSC exon specific primers and were analyzed by direct sequencing. Results: Sequencing analysis identified Ile453Val mutation within exon 7 of CTSC gene in heterozygous condition, and two single nucleotide polymorphisms (SNPs) within intron 2 and 5 in homozygous condition. Conclusion: The present study has identified for the first time the association of Ile453Val mutation within exon 7 and the two SNPs in a subject with HMS.

scholarly journals Combined genetic analysis of juvenile idiopathic arthritis clinical subtypes identifies novel risk loci, target genes and key regulatory mechanisms

2020 ◽  
pp. annrheumdis-2020-218481 ◽  
Author(s):  
Elena López-Isac ◽  
Samantha L Smith ◽  
Miranda C Marion ◽  
Abigail Wood ◽  
Marc Sudman ◽  
...  
Keyword(s):  
Juvenile Idiopathic Arthritis ◽  
Fine Mapping ◽  
Target Genes ◽  
Genome Wide Association Study ◽  
Disease Risk ◽  
Enrichment Analysis ◽  
Joint Analysis ◽  
Integrative Approach ◽  
Nucleotide Polymorphisms ◽  
A Genome

ObjectivesJuvenile idiopathic arthritis (JIA) is the most prevalent form of juvenile rheumatic disease. Our understanding of the genetic risk factors for this disease is limited due to low disease prevalence and extensive clinical heterogeneity. The objective of this research is to identify novel JIA susceptibility variants and link these variants to target genes, which is essential to facilitate the translation of genetic discoveries to clinical benefit.MethodsWe performed a genome-wide association study (GWAS) in 3305 patients and 9196 healthy controls, and used a Bayesian model selection approach to systematically investigate specificity and sharing of associated loci across JIA clinical subtypes. Suggestive signals were followed-up for meta-analysis with a previous GWAS (2751 cases/15 886 controls). We tested for enrichment of association signals in a broad range of functional annotations, and integrated statistical fine-mapping and experimental data to identify target genes.ResultsOur analysis provides evidence to support joint analysis of all JIA subtypes with the identification of five novel significant loci. Fine-mapping nominated causal single nucleotide polymorphisms with posterior inclusion probabilities ≥50% in five JIA loci. Enrichment analysis identified RELA and EBF1 as key transcription factors contributing to disease risk. Our integrative approach provided compelling evidence to prioritise target genes at six loci, highlighting mechanistic insights for the disease biology and IL6ST as a potential drug target.ConclusionsIn a large JIA GWAS, we identify five novel risk loci and describe potential function of JIA association signals that will be informative for future experimental works and therapeutic strategies.

Selection of Genes and Single Nucleotide Polymorphisms for Fine Mapping Starting From a Broad Linkage Region

2007 ◽  
Vol 10 (6) ◽  
pp. 871-885 ◽  
Author(s):  
An Windelinckx ◽  
Robert Vlietinck ◽  
Jeroen Aerssens ◽  
Gaston Beunen ◽  
Martine A. I. Thomis
Keyword(s):  
Linkage Disequilibrium ◽  
Candidate Gene ◽  
Candidate Genes ◽  
Fine Mapping ◽  
Complex Disease ◽  
Gene Selection ◽  
Candidate Gene Approach ◽  
Nucleotide Polymorphisms ◽  
Single Nucleotide ◽  
Selection Of

AbstractFine mapping of linkage peaks is one of the great challenges facing researchers who try to identify genes and genetic variants responsible for the variation in a certain trait or complex disease. Once the trait is linked to a certain chromosomal region, most studies use a candidate gene approach followed by a selection of polymorphisms within these genes, either based on their possibility to be functional, or based on the linkage disequilibrium between adjacent markers. For both candidate gene selection and SNP selection, several approaches have been described, and different software tools are available. However, mastering all these information sources and choosing between the different approaches can be difficult and time-consuming. Therefore, this article lists several of these in silico procedures, and the authors describe an empirical two-step fine mapping approach, in which candidate genes are prioritized using a bioinformatics approach (ENDEAVOUR), and the top genes are chosen for further SNP selection with a linkage disequilibrium based method (Tagger). The authors present the different actions that were applied within this approach on two previously identified linkage regions for muscle strength. This resulted in the selection of 331 polymorphisms located in 112 different candidate genes out of an initial set of 23,300 SNPs.

scholarly journals 11 Million SNP Reference Profiles for Identity Searching Across Ethnicities, Kinship, and Admixture

2018 ◽  
Author(s):  
Brian S. Helfer ◽  
Darrell O. Ricke
Keyword(s):  
Single Nucleotide Polymorphisms ◽  
High Throughput ◽  
Family Relationships ◽  
In Silico ◽  
High Throughput Sequencing ◽  
Genetic Data ◽  
Nucleotide Polymorphisms ◽  
Mixture Analysis ◽  
Single Nucleotide ◽  
Public Repositories

AbstractHigh throughput sequencing (HTS) of single nucleotide polymorphisms (SNPs) provides additional applications for DNA forensics including identification, mixture analysis, kinship prediction, and biogeographic ancestry prediction. Public repositories of human genetic data are being rapidly generated and released, but the majorities of these samples are de-identified to protect privacy, and have little or no individual metadata such as appearance (photos), ethnicity, relatives, etc. A reference in silico dataset has been generated to enable development and testing of new DNA forensics algorithms. This dataset provides 11 million SNP profiles for individuals with defined ethnicities and family relationships spanning eight generations with admixture for a panel with 39,108 SNPs.

scholarly journals Evidence of adoption, monozygotic twinning, and low inbreeding rates in a large genetic pedigree of polar bears

2015 ◽  
Author(s):  
René M. Malenfant ◽  
David W. Coltman ◽  
Evan S. Richardson ◽  
Nicholas J. Lunn ◽  
Ian Stirling ◽  
...  
Keyword(s):  
Mating Systems ◽  
Parentage Analysis ◽  
Hudson Bay ◽  
Polar Bears ◽  
Nucleotide Polymorphisms ◽  
Single Nucleotide ◽  
Monozygotic Twinning ◽  
Close Relatives ◽  
Free Ranging ◽  
First Time

Multigenerational pedigrees have been developed for free-ranging populations of many species, are frequently used to describe mating systems, and are used in studies of quantitative genetics. Here, we document the development of a 4449-individual pedigree for the Western Hudson Bay subpopulation of polar bears (Ursus maritimus), created from relationships inferred from field and genetic data collected over six generations of bears sampled between 1966 and 2011. Microsatellite genotypes for 22-25 loci were obtained for 2945 individuals, and parentage analysis was performed using the program FRANZ, including additional offspring-dam associations known only from capture data. Parentage assignments for a subset of 859 individuals were confirmed using an independent medium-density set of single nucleotide polymorphisms. To account for unsampled males in our population, we performed half-sib/full-sib analysis to reconstruct males using the program COLONY, resulting in a final pedigree containing 2957 assigned maternities and 1861 assigned paternities with only one observed case of inbreeding between close relatives. During genotyping, we identified two independently captured two-year-old males with identical genotypes at all 25 loci, showing--for the first time--a case of monozygotic twinning among polar bears. In addition, we documented six new cases of cub adoption, which we attribute to cub misidentification or misdirected maternal care by a female bereaved of her young. Importantly, none of these adoptions could be attributed to reduced female vigilance caused by immobilization to facilitate scientific handling, as has previously been suggested.

scholarly journals Role of GSPT1 and GSPT2 polymorphisms in different outcomes upon Hepatitis B virus infection and prognosis to lamivudine therapy

2019 ◽  
Vol 39 (3) ◽  
Author(s):  
Wenxuan Liu ◽  
Ning Ma ◽  
Xia Gao ◽  
Wencong Liu ◽  
Jinhai Jia ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Single Nucleotide Polymorphisms ◽  
Nucleotide Polymorphisms ◽  
Lamivudine Therapy ◽  
Single Nucleotide ◽  
Tumor Susceptibility ◽  
B Virus ◽  
First Time

Abstract Purpose. ERF3, having been found expressing differently in liver tissues in our previous work, including eRF3a and eRF3b, which are structural homologs named GSPT1 and GSPT2. Recent studies have indicated that eRF3b involved in the development and proliferation of HepG2 cell, and eRF3a may be associated with tumor susceptibility. Based on this, we tested the effects of GSPT1 and GSPT2 single-nucleotide polymorphisms for all major Hepatitis B virus (HBV) outcomes and lamivudine (LAM) treatment in Han Chinese. Method. A total of 1649 samples were enrolled, and peripheral blood samples were collected in the present study. The single-nucleotide polymorphisms in the GSPT1 and GSPT2 region were genotyped using MALDI-TOF MS. Results. Our study demonstrated there was no obvious relevance of either GSPT1-rs33635 or GSPT2-rs974285 polymorphisms with HBV susceptibility, spontaneous recovery, and development of HBV-related diseases. However, we showed for the first time to our knowledge that GSPT1-rs33635C was a predictor for LAM therapy (viral response: odds ratio (OR) = 2.436, P=0.022; biochemical response: OR = 3.328, P=1.73 × 10−4). Conclusions. These findings might provide potential implications for therapeutic guidance.

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