Epigenetic association analysis of clinical sub-phenotypes in patients with polycystic ovary syndrome (PCOS)
Polycystic ovarian syndrome (PCOS) is a complex disorder affecting up to 15–20% of reproductive women. PCOS has recently been investigated using genome-wide association studies revealing important mutations and DNA methylation sites associated with the syndrome. As a clinically highly heterogenous condition, studying the molecular basis of the differential manifestation of PCOS is both meaningful concerning individualized management and important for understanding the biology of PCOS. Using genome-wide DNA methylation data collected from PCOS patients, we performed a powerful region-based analysis to detect differentially methylated regions (DMR) by correlating DNA methylation pattern in a genomic region with the level of each PCOS clinical sub-phenotype. We identified seven significant DMRs on chromosome 19 (12877188-12876846 bp) and chromosome 6 (MHC region) associated with prolactin level, as well as chromosomes 11 and 2 associated with metabolic attributes. Functional annotation linked significant DNA methylation patterns to functional genes (HOOK2, BDNFl, HLA-G, HLA-H, HLA-J, RNF39, etc) of metabolic disorders and immunity or novel associations to serve as targets for validation and replication.