DDX3X and Intellectual disability: Amongst the OGT and OGA correlated genes implicated in cell cycle regulation, the gene encoding the RNA helicase DDX3X, an RNA helicase linked to S-phase entry and intellectual disability, was among the strongest OGT/OGA correlated genes (r = 0.68 and r = 0.74, respectively; figure 1A) [29,33,38].