Germline monoallelic pathogenic variants in PTPN11, KRAS, HRAS, BRAF, RAF1, RIT1, SOS1, SOS2, and RASA1 have been identified in individuals with CCLA and Noonan syndrome, CCLA and Costello syndrome, CCLA and cardiofaciocutaneous syndrome, or CCLA and capillary malformation-arteriovenous malformation syndrome (48, 61, 80–88). This evidence concerns the gene RASA1 and capillary malformation.