NSD1 and Beckwith-Wiedemann syndrome: Interestingly, a study conducted on an overgrowth syndrome characterized by NSD1 deficiency [99], a molecular defect found in a subset of BWS, demonstrated the role of NSD1 as a specific co-activator for a novel enhancer in DMR0 affecting IGF2-p0 transcriptional activity in a cell-type-specific manner.