Velo-cardio-facial syndrome (VCFS), a syndrome characterized by an increased frequency of schizophrenia and bipolar disorder, is associated with small interstitial deletions of chromosome 22q11.
We evaluated 50 adults with VCFS using a structured clinical interview (Schedules for Clinical Assessment in Neuropsychiatry or Psychiatric Assessment Schedule for Adults With Developmental Disability if IQ <50) to establish a DSM-IV diagnosis. The schizophrenia phenotype in individuals with VCFS and schizophrenia was compared with a matched series of individuals with schizophrenia and without VCFS (n=12). The King's Schizotypy Questionnaire was administered to individuals with VCFS (n=41), their first-degree relatives (n=68), and a series of unrelated normal controls (n=316). All individuals with VCFS deleted for the N25 probe (n=48) were genotyped for a genetic polymorphism in the COMT gene that results in variations in enzymatic activity.
Fifteen individuals with VCFS (30%) had a psychotic disorder, with 24% (n=12) fulfilling DSM-IV criteria for schizophrenia. In addition, 6 (12%) had major depression without psychotic features. The individuals with schizophrenia had fewer negative symptoms and a relatively later age of onset compared with those with schizophrenia and without VCFS. We found no evidence that possession of the low-activity COMT allele was associated with schizophrenia in our sample of individuals with VCFS.
The high prevalence of schizophrenia in this group suggests that chromosome 22q11 might harbor a gene or genes relevant to the etiology of schizophrenia in the wider population.