Dataset Information

Conjunctival fibrosis and the innate barriers to Chlamydia trachomatis intracellular infection: a genome wide association study

ABSTRACT: This data comes from a genome-wide association study in 1090 cases of scarring trachoma and 1531 controls from a non-selected multi-ethnic sampling of The Gambia. The data constitutes hard base calls at 1457295 features from the HumanOmni2.5-8 (Omni2.5) BeadChip. Three genotype-calling algorithms were used : Illuminus (Bioinformatics 2007, 23:2741–6), GenCall (Patent US7035740, 2006) and GenoSNP (Bioinformatics 2008, 24:2209–14). Data from each calling algorithm was filtered to retain only SNPs with a call rate ≥ 0.98. To obtain a merged set of SNPs, all genotypes that matched across call-sets were retained, whilst those that mismatched between call-sets were set to missing. Genotypes that were present in one call set and missing in others were also retained. The merged SNP set contained 1467876 SNPs, which were filtered for call rate ≥ 0.99 and Hardy-Weinberg equilibrium P value < 5 x 10-8. The case and control groups were approximately equivalent with respect to gender and ethnicity. 70% of cases and 63% of controls were female. Self-described ethnic composition of the cases was 29% Jola, 27% Mandinka, 21% Wolof, 10% Fula and 13% other/no data. In controls the composition was 25% Jola, 24% Mandinka, 21% Wolof, 8% Fula and 22% other/no data. Median age was 49 (range 32-60) in cases and 37 (range 12-52) in controls (t = -3.6019, P = 0.0003). This data set has substantial levels of population structure, which reflects extensive networks of pairwise kinship between participants. First pass tests of association in EMMAX (Nat Genet 2010, 42:348–54) led to genome-wide deflation of the test statistics (λ = 0.982 SE = 1.74e-05) that could be directly attributed to the differing age and gender distributions between cases and controls. Modelling the phenotype to adjust for age and gender successfully controlled for this and no genome-wide deviation from the null was subsequently observed (λ = 1.001, SE = 8.7 x 10-7). Neither principal components analysis (PCA) nor tests of proportional identity by state (IBS) variance in PLINK identified significant levels of within or between group genetic variance. The phenotypes submitted in the phenotypes file include both uncorrected (case/control status) and corrected (age and gender corrected case/control status) phenotypes, as well as age and self-described ethnicity.

PROVIDER: EGAS00001001516 | EGA |

REPOSITORIES: EGA

ACCESS DATA

Publications

Conjunctival fibrosis and the innate barriers to Chlamydia trachomatis intracellular infection: a genome wide association study.

Roberts Chrissy h Ch Franklin Christopher S CS Makalo Pateh P Joof Hassan H Sarr Isatou I Mahdi Olaimatu S OS Sillah Ansumana A Bah Momodou M Payne Felicity F Jeffreys Anna E AE Bottomley William W Natividad Angels A Molina-Gonzalez Sandra S Burr Sarah E SE Preston Mark M Kwiatkowski Dominic D Rockett Kirk A KA Clark Taane G TG Burton Matthew J MJ Mabey David C W DC Bailey Robin R Barroso Inês I Holland Martin J MJ

Scientific reports 20151130

Chlamydia trachomatis causes both trachoma and sexually transmitted infections. These diseases have similar pathology and potentially similar genetic predisposing factors. We aimed to identify polymorphisms and pathways associated with pathological sequelae of ocular Chlamydia trachomatis infections in The Gambia. We report a discovery phase genome-wide association study (GWAS) of scarring trachoma (1090 cases, 1531 controls) that identified 27 SNPs with strong, but not genome-wide significant, ...[more]

PMID: 26616738

Similar Datasets

Project description:We have explored the potential role of genetics in the development of osteonecrosis of the jaw (ONJ) in multiple myeloma (MM) patients under bisphosphonate therapy. A genome wide association study was performed using 500.568 single nucleotide polymorphisms (SNPs) in two series of homogeneously treated MM patients: one with ONJ (22 MM cases) and another without ONJ (65 matched MM controls). Four SNPs (rs1934951, rs1934980, rs1341162 and rs17110453) mapped within the Cytochrome P450-2C gene (CYP2C8) showed a different distribution between cases and controls with statistically significant differences (p=1.07x10-6, p=4.231x10-6, p=6.22x10-6 and p=2.15x10-5, respectively). SNP rs1934951 was significantly associated with a higher risk of ONJ development even after Bonferroni correction (P corrected value=0.02). Genotyping results displayed an overrepresentation of the T allele in cases as compared with controls (48% vs. 12%). Thus, individuals homozygous for the T allele had an increased likelihood of developing ONJ (Odds ratio 12.75, 95% confidence interval 3.7 to 43.5). We studied 22 cases (MM with ONJ) and 65 controls (MM without ONJ), matched for age, gender and ethnicity (note: all of the cases and controls are Caucasian). All patients were enrolled in the GEM-00 protocol, which consists on polychemotherapy and autologous transplantation. All received BPs therapy, either Pamidronate (16 cases, 57 controls) or Zoledronic Acid (6 cases, 8 controls) planned for 2 years (median 22 months, range 9-24 months). Clinical characteristics were similar between controls and cases. Study protocols were approved by the ethics committee and written informed consent was obtained from all participants. Each patient was genotyped using the Affymetrix GeneChip Mapping 500K set of microarrays (Affymetrix, Santa Clara, CA) according to the manufacturer’s recommendations. Genotypes were determined using the BRLMM algorithm with cases and controls undergoing joint cluster analysis, after ensuring a robust association test through quality filtering tests. Based on stringent quality control criteria a total of 339.972 SNPs were selected for subsequent analyses. Criteria for exclusion were: 1) call rate<90%, 2) minor allele frequency <5% and 3) deviations from Hardy-Weinberg equilibrium with a p<0.00001. Sexual chromosomes were excluded for analysis. To test for allelic associations between SNPs and ONJ, we constructed 2x2 contingency tables and compared using the two-sided Fisher’s exact or Chisquare tests through SPSS software (SPSS 14.0, Inc. Chicago, IL, USA). P-values were corrected (Pc) using the Bonferroni correction. The strength of association was estimated by the odds ratio (OR), and their 95% confidence intervals (CI) were calculated by Cornfield methods. Linkage disequilibrium between SNPs was analyzed using the Arlequin Software (http://anthro.unige.ch/arlequin).

Dataset Information

Conjunctival fibrosis and the innate barriers to Chlamydia trachomatis intracellular infection: a genome wide association study

Publications

Conjunctival fibrosis and the innate barriers to Chlamydia trachomatis intracellular infection: a genome wide association study.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure