Prenatal overgrowth and polydramnios: would you think about Noonan syndrome?

Abstract

We report on a child with prenatal findings of increased nuchal translucency, polydramnios, ascites and overgrowth. At birth she presented length >97° centile, minor facial anomalies, megalencephaly and Wolff-Parkinson-White syndrome. Whole Exome Sequencing showed a pathogenic variant in the NRAS gene, but no mutations were found in PI3K/AKT/mTOR pathway genes.