title: The schizophrenia phenotype in 22q11 deletion syndrome.
abstract: OBJECTIVE
  This study investigated the schizophrenia phenotype in 24 subjects with 22q11 deletion syndrome (22qDS) and schizophrenia (22qDS-schizophrenia), a rare but relatively homogenous genetic subtype of schizophrenia associated with a microdeletion on chromosome 22. Individuals with 22qDS are at genetically high risk for schizophrenia.
  
  
  METHODS
  Standard measures of signs, symptoms, and course of schizophrenia were assessed in 16 adults with 22qDS-schizophrenia who did not meet criteria for mental retardation and in 46 adults with schizophrenia without evidence of 22qDS from a community familial sample.
  
  
  RESULTS
  There were no significant differences in age at onset, lifetime or cross-sectional core positive and negative schizophrenic symptoms, or global functioning between the two groups of patients with schizophrenia. Patients with 22qDS-schizophrenia had higher excitement subscale scores and less lifetime substance use than the comparison patients with schizophrenia, but no significant differences in anxiety-depression symptom severity were found between the groups.
  
  
  CONCLUSIONS
  These findings indicate that the core clinical schizophrenia phenotype would not distinguish individuals with a 22qDS subtype from those with schizophrenia who did not have the 22qDS subtype. The results provide further support for the utility of 22qDS-schizophrenia as a neurodevelopmental model of schizophrenia as well as support for prospective studies of individuals with 22qDS to help identify precursors of schizophrenia.
authors.affiliation: Centre for Addiction and Mental Health, Department of Psychiatry, University of Toronto, 1001 Queen Street West, Toronto, Ontario, M6J 1H4 Canada. anne.bassett@utoronto.ca
authors.forename: Anne S
authors.initials: AS
authors.lastname: Bassett
authors.forename: Eva W C
authors.initials: EW
authors.lastname: Chow
authors.forename: Philip
authors.initials: P
authors.lastname: AbdelMalik
authors.forename: Mirona
authors.initials: M
authors.lastname: Gheorghiu
authors.forename: Janice
authors.initials: J
authors.lastname: Husted
authors.forename: Rosanna
authors.initials: R
authors.lastname: Weksberg
mesh_terms: D000328:Adult; D017668:Age of Onset; D001008:Anxiety Disorders / Q000175:diagnosis; D002892:Chromosomes, Human, Pair 22 / Q000235:genetics*; D015897:Comorbidity; D003866:Depressive Disorder / Q000175:diagnosis; D003937:Diagnosis, Differential; D005260:Female; D017353:Gene Deletion; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D011569:Psychiatric Status Rating Scales; D012559:Schizophrenia / Q000175:diagnosis / Q000453:epidemiology / Q000235:genetics*; D012565:Schizophrenic Psychology; D012720:Severity of Illness Index; D019966:Substance-Related Disorders / Q000175:diagnosis / Q000453:epidemiology