Clinically detectable copy number variations in a Canadian catchment population of schizophrenia

Copy number variation (CNV) is a highly topical area of research in schizophrenia but the clinical relevance is uncertain and the translation to clinical practice is under-studied There is a paucity of research involving truly community-based samples of schizophrenia and widely available laboratory techniques Our objective was to determine the prevalence of clinically detectable CNVs in a community sample of schizophrenia while mimicking typical clinical practice conditions We used a brief clinical screening protocol for developmental features in adults with schizophrenia for identifying individuals with 22q11 2 deletions and karyotypically detectable chromosomal anomalies in 204 consecutive patient, with schizophrenia from a single Canadian catchment area Twenty-seven (13 2%) subjects met clinical criteria for a possible syndrome and 26 of these individuals received clinical genetic testing Five of them representing 2 5% of the total sample (95% CI 0 3%-4 6%) including two of ten patients with mental retardation had clinically detectable anomalies two 22q11 2 deletions (1 0%) one 47 XYY and two other novel CNVs - an 8p23 3-p23 1 deletion and a de novo 19p13 3-p13 2 duplication The results support the utility of screening and genetic testing to identify genetic syndromes in adults with schizophrenia in clinical practice Identifying large rare CNVs (particularly 22q11 2 deletions) can lead to significant changes in management follow-up and genetic counselling that are helpful to the patient family and clinicians (C) 2010 Elsevier Ltd All rights reserved