Noonan syndrome: psychological and psychiatric aspects

Although Noonan syndrome (NS) is a disorder with a relatively high prevalence, virtually no information in adult patients is available about the psychological and psychopathological profile. In the present clinical report the first series of 10 NS patients from an ongoing project is presented. The purpose of the study is to investigate the psychopathology, social cognition and adaptation as well as the quality of life in NS patients aged 16 years or more. PTPN11 mutations were present in six patients and KRAS and SOS1 in one patient, respectively. In two patients no known mutation was found. The results demonstrate a variable level of intelligence and suggest moderately impaired social cognition in terms of emotion recognition and alexithymia. In some patients mild signs of anxiety and lowered mood are found that, however, do not meet the criteria for a specific psychiatric disorder. It is concluded that NS in adults is associated with a behavioral phenotype in which deficiencies in social and emotional recognition and expression may be key elements.