The neurofibromatosis-Noonan syndrome: genetic heterogeneity versus clinical variability. Case report and review of the literature.

We report on a discordant twin male with neurofibromatosis and manifestations of the Noonan syndrome. He has multiple café-au-lait spots and axillary freckling, relative macrocephaly, ptosis, mid-face hypoplasia, short neck and pulmonic stenosis. The presence of neurofibromatosis associated with Noonan syndrome phenotype in our patient raises the question of a unique disorder sharing characteristics of both conditions.