Noonan syndrome and RASopathies — branching viva

Postnatal ward: a newborn with a Turner-like phenotype (triangular face, hypertelorism, ptosis, webbed neck, widely spaced nipples), a 46,XY karyotype, and an echocardiogram showing pulmonary valve stenosis with dysplastic leaflets. The examiner asks: what is the unifying diagnosis, how do you confirm it, and what is the surveillance plan — then branches to the same child presenting with a bleeding episode before dental extraction, and finally to a different infant with coarse features, deep creases, and hypertrophic cardiomyopathy.