Twelve participants were identified with a 2p24.3 microduplication that included the DDX1 locus but not MYCN, none of whom received a diagnosis of a childhood embryonal tumour.<h4>Interpretation</h4>We have shown that 2p24.3 microduplications that include MYCN predispose to childhood embryonal tumours and should be routinely assessed when WT or neuroblastoma predisposition is suspected. The gene discussed is MYCN; the disease is embryonal neoplasm.