The concept of neuro-cardio-facio-cutaneous (NCFC) syndrome has recently been formulated in order to bring together a number of hereditary diseases that include a number of shared phenotypic features to differing degrees: (i) craniofacial dysmorphia; (ii) delayed growth; (iii) mental retardation or learning difficulties; (iv) cardiac malformations (most commonly pulmonary valve stenosis and hypertrophic cardiomyopathy); (v) cutaneous anomalies, and in some cases, predisposition to certain forms of malignant solid tumors and blood diseases, associated at the physiopathological level with deregulation of the Ras-MAP kinase cellular signaling pathways 1. NCFC subsumes neurofibromatosis type1, Legius syndrome, LEOPARD syndrome, Noonan syndrome, Costello syndrome and cardiofaciocutaneous (CFC) syndrome. While the majority of these diseases are readily distinguishable in clinical terms, with or without diagnostic criteria, none of them have any pathognomonic signs. Many cases attest to the strong clinical homologies and forms of overlapping between these different diseases. In recent years, the discovery of germinal mutations of these different diseases has in fact reinforced the unifying clinical and biochemical concept of NCFC syndrome.