Non-HLA gene polymorphisms in juvenile idiopathic arthritis: associations with disease outcome
SCANDINAVIAN JOURNAL OF RHEUMATOLOGY
Authors: Alberdi-Saugstrup, M.; Enevold, C.; Zak, M.; Nielsen, S.; Nordal, E.; Berntson, L.; Fasth, A.; Rygg, M.; Muller, K.
Abstract
Objective: To test the hypothesis that non-HLA single-nucleotide polymorphisms (SNPs) associated with the risk of juvenile idiopathic arthritis (JIA) are risk factors for an unfavourable disease outcome at long-term follow-up.Methods: The Nordic JIA cohort is a prospective multicentre study cohort of patients from the Nordic countries. In all, 193 patients met the inclusion criteria of having an 8year follow-up assessment and available DNA sample. Seventeen SNPs met the inclusion criteria of having significant associations with JIA in at least two previous independent study cohorts. Clinical endpoints were disease remission, actively inflamed joints and joints with limitation of motion (LOM), articular or extra-articular damage, and history of uveitis.Results: Evidence of associations between genotypes and endpoints were found for STAT4, ADAD1-IL2-IL21, PTPN2, and VTCN1 (p=0.003-0.05). STAT4_rs7574865 TT was associated with the presence of actively inflamed joints [odds ratio (OR) 20.6, 95% confidence interval (CI) 2.2->100, p=0.003] and extra-articular damage (OR 7.9, 95% CI 1-56.6, p=0.057). ADAD1_rs17388568 AA was associated with a lower risk of having joints with LOM (OR 0.1, 95% CI 0-0.55, p=0.016). PTPN2_rs1893217 CC was associated with a lower risk of having joints with LOM (OR 0.2, 95% CI 0-0.99, p=0.026), while VTCN1_rs2358820 GA was associated with uveitis (OR 3.5, 95% CI 1-12.1, p=0.029).Conclusion: This exploratory study, using a prospectively followed JIA cohort, found significant associations between long-term outcome and SNPs, all previously associated with development of JIA and involved in immune regulation and signal transduction in immune cells.
Enhancer Connectome Nominates Target Genes of Inherited Risk Variants from Inflammatory Skin Disorders
JOURNAL OF INVESTIGATIVE DERMATOLOGY
Authors: Jeng, Mark Y.; Mumbach, Maxwell R.; Granja, Jeffrey M.; Satpathy, Ansuman T.; Chang, Howard Y.; Chang, Anne Lynn S.
Abstract
The vast majority of polymorphisms for human dermatologic diseases fall in noncoding DNA regions, leading to difficulty interpreting their functional significance. Recent work using chromosome conformation capture technology in combination with chromatin immunoprecipitation (ChIP) has provided a systematic means of linking noncoding variants in active enhancer loci to putative gene targets. Here, we apply H3K27ac HiChIP high-resolution contact maps, generated from primary human T-cell subsets (CD4(+) naive, T helper type 17, and regulatory T cells), to 21 dermatologic conditions associated with single nucleotide polymorphisms from 106 genome-wide association studies. This " enhancer connectome" identified 1,492 HiChIP gene targets from 542 noncoding SNPs (P <= 5.0 x 10(-8)). SNP-containing enhancers from inflammatory skin conditions were significantly enriched at the HLA locus and also targeted several key factors from the JAK-STAT signaling pathway, but nonimmune conditions were not. A focused profiling of systemic lupus erythematosus HiChIP genes identified enhancer interactions with factors important for effector CD4(+) T-cell differentiation and function, including IRF8 and members of the Ikaros family of zinc-finger proteins. Our results show the ability of the enhancer connectome to nominate functionally relevant candidates from genome-wide association studye-dentified variants, representing a powerful tool to guide future studies into the genomic regulatory mechanisms underlying dermatologic diseases.