A group of genetic disorders associated with mutation(s) in genes that are constituents of the RAS signaling pathway. These disorders are characterized by distinct facial features, developmental delays, cardiac defects, growth delays, and feeding problems. Representative examples include: neurofibromatosis type 1, capillary malformation-arteriovenous malformation syndrome, cardiofaciocutaneous syndrome, Costello syndrome, multiple lentigines syndrome, and Noonan syndrome. [from
NCI]