Maas et al. performed a literature review evaluating reported data from 1971 BWSp patients.5 155/1923 (8%) of BWSp children developed tumours (IC2-LOM 2.6% with cancer, IC1-GOM 28%, UPDpat 16% and pathogenetic variants in CDKN1C 6.9%). This evidence concerns the gene CDKN1C and cancer.