The behavioral phenotype and psychiatric symptoms of 21 children with Noonan’s syndrome are reported from the Departments of Child and Adolescent Psychiatry, and Clinical Genetics, Royal Manchester Children’s Hospital, UK. Ages ranged from 2 to 16 years (median, 9 years). Non-behavioral abnormalities included pregnancy complications (52%), short stature (71%), visual problems (57%), and language impairment (43%). Behavioral abnormalities in >50% of the group included clumsiness (71%), faddy eating habits (67%), fidgeting (62%), stubbornness (62%), echolalia (52%), euphoria (52%), and irritability (52%). On the Child Behavior Checklist for parent reported psychiatric abnormalities, only social relationships and attention span were disturbed, and these are non-specific. A behavioral profile for Noonan’s syndrome is suggested by these findings but compared to sibling controls, the abnormalities were not statistically significant. 
COMMENT. Noonan’s syndrome is a genetic disorder characterized by pulmonary stenosis, facial abnormalities, short stature, and learning difficulties. Few studies have emphasized behavioral abnormalities and a behavioral phenotype has not been delineated. The above behavioral characteristics may be helpful in diagnosis, counselling, and treatment. The association of Noonan’s syndrome and neurofibromatosis has been described. (Listernick, Charrow, 1990; see Progress in Ped Neur II, 1994, p377).