Therefore, the phenotypic and molecular characterisation of other patients with BWSp who have developed some type of neoplasm, mainly from the neural crest, and functional studies of loss-of-function CDKN1C variants on neural crest tumour development are important to better understanding the relationship between loss-of-function CDKN1C variants and these tumour types. The gene discussed is CDKN1C; the disease is neoplasm.