A large sample (a final sample size of 100-120 is anticipated) of children with 22q11DS, aged 10 - 20 year, is broadly phenotyped using standard psychiatric assessment methods, intelligence and selected neuropsychological tests as well as psychophysiological assessments. Approximately 4 years after the initial assessment a follow up assessment is planned. Age and IQ matched children without the deletion (or any other apparent genetic abnormality) are used as a control group.