POFUT1 and Dowling-Degos disease 1: Both POGLUT1 and POFUT1, causative genes in DDD, are established regulators of Notch pathway activity through their respective protein products namely protein-O glucosyltransferase 1 and protein O-fucosyltransferase 1 (Li et al., 2013; Basmanav et al., 2014).