[Noonan syndrome: differential diagnosis with Turner's syndrome]

Clinical and laboratory evidences assure an unequivocal identity to the syndrome described by Noonan. We believed that the terminology used by many authors has contributed to maintain confusion with Turner's syndrome from which it is clearly differenciated. The signology of both syndromes was confrontated in order to delineate the syndrome. Emphasis was made to point out the signs which are proper to each syndrome and the signs which are common to both of them stressing those that, occur with equal or significant difference. Two new signs are described in Noonan syndrome: alopecia of the hund portions of the eyebrows and keratosis rubra pilaris (Ulerythema ophriogenes).