Figure 3.

Facial dysmorphism and other features of subjects with Noonan syndrome heterozygous for mutations in the SOS1 gene. SOS1 mutation-positive subjects generally exhibit typical facial features, including macrocephaly, hypertelorism, ptosis, downslanting palpebral fissures, sparse eyebrows with keratosis pylaris, a short and broad nose with upturned tip, low-set and posteriorly angulated ears, and high forehead commonly associated with bitemporal narrowing and prominent supraorbital ridges. Curly hair is present in most of the patients. Other common features include pectus anomalies (NS10, NS19, NS37), short and/or webbed neck (NS6, NS10, NS19, NS22, NS38), and cubitus valgus (NS37). Keloid scars (NS16), recurrent hemorrhages (NS18), and deep plantar creases (NS38) also occur in these subjects. In some infants, the face is suggestive of cardiofaciocutaneous syndrome due to the coarseness of features (NS39).