Genetic, developmental, and physical factors associated with attention deficit hyperactivity disorder in patients with velocardiofacial syndrome.

Velocardiofacial syndrome (VCFS) is a relatively common developmental neuropsychiatric syndrome caused by a 22q11 microdeletion. There is an extensive variability in the phenotypic expression of this disease. The most common psychiatric disorder in VCFS is attention-deficit/hyperactivity disorder (ADHD), affecting 35-55% of patients.