Neuropsychological developmental change in a case with Noonan syndrome: longitudinal assessment.

The authors describe the neuropsychological development of a 10-year-old boy with Noonan syndrome. The subject's IQ showed normal intelligence, although there was a discrepancy between verbal and performance IQs. Visual perception was delayed, with clumsiness and inattention affecting his performance. Both visual perception and hyperactivity improved with the subject's general development, but his inattention seemed to increase after the age of 9. The behavioral features and cognitive profile of our case resembled those of attention-deficit/hyperactivity disorder. We recommend that clinicians should evaluate cautiously the specific profile of cognitive development in Noonan syndrome with particular focus on controlling the patient's inattention.