Neurofibromatosis-Noonan syndrome

Type I neurofibromatosis (NF-1) and Noonan syndrome (NS) are two fairly common genetic disorders. Patients with features of both disorders have been described, but considerable variability of phenotypic expression occurs. As a result, the correct nosology of this syndrome is uncertain. We present a patient with full expression of both NF-1 and NS phenotypes, and discuss the debate regarding the genetics of the combined syndrome.