Prenatal features of Noonan syndrome.

We report six cases of Noonan syndrome which presented prenatally with sonographic abnormalities. These included increased nuchal fluid, short femora, pleural effusions, hydrops, cardiac and renal abnormalities. A review of all cases of Noonan syndrome seen at two regional genetics centres confirms the association with these sonographic abnormalities. These cases demonstrate the diversity of prenatal presentation of Noonan syndrome and highlight the need to consider this diagnosis, particularly when faced with a fetus with a normal karyotype and varying degrees of oedema or hydrops, with a short femur length. Copyright 1999 John Wiley & Sons, Ltd.