Using ROADMAP Data to Identify Enhancers Associated with Disorders of Sex Development

Despite recent advances in our understanding, most cases of disorders of sex development (DSD) cannot be explained by mutations in known genes. In genome-wide screens of DSD patients, we and others detected duplications or deletions of potential regulatory regions of known or suspected DSD genes. It is therefore likely that a significant proportion of DSD cases may be explained by disrupted transcriptional regulation of gonad genes. Despite many recent technological advances, limited availability of relevant tissues - especially human embryonic material - can make the identification of long-range regulatory elements extremely difficult. In an attempt to overcome this limitation, we evaluated the usefulness of publicly available DNaseI hypersensitivity data from the Roadmap Epigenomics Project. For this feasibility study we used the 'gene desert' around the SOX9 gene and a genomic locus downstream of GATA4. Over 60% of our selected candidate regions had significant enhancer activity in luciferase assays. We show that this approach facilitates the detection of strong enhancer candidates worthy of further analysis.