label: neurofibromatosis-Noonan syndrome
label_lc: neurofibromatosis-noonan syndrome
description: A RASopathy and a variant of neurofibromatosis type 1 (NF1) characterized by the combination of features of NF1, such as cafe-au-lait spots, iris Lisch nodules, axillary and inguinal freckling, optic nerve glioma and multiple neurofibromas; and Noonan syndrome (NS), such as short stature, typical facial features (hypertelorism, ptosis, downslanting palpebral fissures, low-set posteriorly rotated ears with a thickened helix, and a broad forehead), congenital heart defects and unusual pectus deformity. As these three entities have significant phenotypic overlap, molecular genetic testing is often necessary for a correct diagnosis (such as when cafC)-au-lait spots are present in patients diagnosed with NS).