Gene regulatory activity associated with PCOS reveals DENND1A-dependent testosterone production

Polycystic Ovary Syndrome (PCOS) is a leading cause of infertility. About 5 million women in the US have PCOS, making it the most prevalent endocrine disorder among menstruating people. Despite that prevalence, the underlying causes remain unknown. Genome-wide association studies (GWAS) have identified non-coding genetic variation associated with PCOS risk and identifying the underlying molecular mechanisms is currently a major opportunity for improving diagnosis and treatment. We report the discovery of gene regulatory mechanisms that help explain genetic association with PCOS in the GATA4, FSHB and DENND1A loci. We based those findings using a combination of high throughput reporter assays, CRISPR-based epigenome editing, and genetic association analysis from PCOS case and control populations. In addition, we found that elevated endogenous DENND1A expression causes elevated testosterone levels, a hallmark PCOS phenotype. These results further highlight the potential for combining genetic variant analyses with experimental approaches to fine map genetic associations with disease risk.