High concentrations of dehydroepiandrosterone sulfate (DHEAS) often precede premature puberty and sometimes polycystic ovary syndrome (PCOS). We hypothesized that the underlying mechanisms might invol Show more
High concentrations of dehydroepiandrosterone sulfate (DHEAS) often precede premature puberty and sometimes polycystic ovary syndrome (PCOS). We hypothesized that the underlying mechanisms might involve DNA methylation. As an indicator of the downstream effects of DHEAS, we looked for associations between prepubertal DHEAS concentration, pubertal progression, and DNA methylation at puberty-related genes in blood cells. Blood methylome and DHEAS concentration at 7.5 and 8.5 years, respectively, were analyzed in 91 boys and 82 girls. Pubertal development data were collected between 8.1 and 17 years (all from UK birth cohort, Avon Longitudinal Study of Parents and Children [ALSPAC]). Correlation between DHEAS and pubertal measurements was assessed by Spearman's correlation. DHEAS association with methylation at individual CpGs or regions was evaluated by linear regression, and nearby genes examined by enrichment analysis and intersection with known puberty-related genes. Boys and girls with higher childhood DHEAS concentrations had more advanced pubic hair growth throughout puberty; girls also had advanced breast development, earlier menarche, and longer menstrual cycles. DHEAS concentration was associated with methylation at individual CpGs near several puberty-related genes. In boys, 14 genes near CpG islands with DHEAS-associated methylation were detected, and in girls, there were 9 which included LHCGR and SRD5A2; FGFR1 and FTO were detected in both sexes. The association between DHEAS and pubertal development, as reported previously, suggests a physiological connection. Our novel findings showing that DHEAS concentration correlates negatively and linearly with DNA methylation levels at regulatory regions of key puberty-related genes, provide a mechanism for such a functional relationship. Show less
In a genome-wide association study of Caucasian patients with juvenile idiopathic arthritis (JIA), we have previously described findings limited to autoimmunity loci shared by JIA and other diseases. Show more
In a genome-wide association study of Caucasian patients with juvenile idiopathic arthritis (JIA), we have previously described findings limited to autoimmunity loci shared by JIA and other diseases. The present study was undertaken to identify novel JIA-predisposing loci using genome-wide approaches. The discovery cohort consisted of Caucasian JIA cases (n = 814) and local controls (n = 658) genotyped on the Affymetrix Genome-Wide SNP 6.0 Array, along with 2,400 out-of-study controls. In a replication study, we genotyped 10 single-nucleotide polymorphisms (SNPs) in 1,744 cases and 7,010 controls from the US and Europe. Analysis within the discovery cohort provided evidence of associations at 3q13 within C3orf1 and near CD80 (rs4688011) (odds ratio [OR] 1.37, P = 1.88 × 10(-6) ) and at 10q21 near JMJD1C (rs647989 [OR 1.59, P = 6.1 × 10(-8) ], rs12411988 [OR 1.57, P = 1.16 × 10(-7) ], and rs10995450 [OR 1.31, P = 6.74 × 10(-5) ]). Meta-analysis provided further evidence of association for these 4 SNPs (P = 3.6 × 10(-7) for rs4688011, P = 4.33 × 10(-5) for rs6479891, P = 2.71 × 10(-5) for rs12411988, and P = 5.39 × 10(-5) for rs10995450). Gene expression data on 68 JIA cases and 23 local controls showed cis expression quantitative trait locus associations for C3orf1 SNP rs4688011 (P = 0.024 or P = 0.034, depending on the probe set) and JMJD1C SNPs rs6479891 and rs12411988 (P = 0.01 or P = 0.04, depending on the probe set and P = 0.008, respectively). Using a variance component liability model, it was estimated that common SNP variation accounts for approximately one-third of JIA susceptibility. Genetic association results and correlated gene expression findings provide evidence of JIA association at 3q13 and suggest novel genes as plausible candidates in disease pathology. Show less