Mutations of four genes have been associated to CFCS: BRAF (7q34), MAP 2 K1 (15q22.31), MAP 2 K2 (19p13.3, Cardio-facio-cutaneous syndrome 4, OMIM #615280), and KRAS (12p12.1). This evidence concerns the gene KRAS and cardiofaciocutaneous syndrome 1.