Brief Research Communication
Assessment of the frequency of the 22q11 deletion in Afrikaner schizophrenic patients
Article first published online: 2 JUN 2004
Copyright © 2004 Wiley-Liss, Inc.
American Journal of Medical Genetics Part B: Neuropsychiatric Genetics
Volume 129B, Issue 1, pages 20–22, 15 August 2004
How to Cite
Wiehahn, G.J., Bosch, G.P., du Preez, R.R., Pretorius, H.W., Karayiorgou, M. and Roos, J.L. (2004), Assessment of the frequency of the 22q11 deletion in Afrikaner schizophrenic patients. Am. J. Med. Genet., 129B: 20–22. doi: 10.1002/ajmg.b.20168
- Issue published online: 19 JUL 2004
- Article first published online: 2 JUN 2004
- Manuscript Accepted: 21 OCT 2003
- Manuscript Received: 17 MAR 2003
- 22q11 deletion;
A hemizygous deletion of the q11 band on chromosome 22 occurs in 1 of every 5,950 live births (0.017%). The deletion is mediated by low copy repeats (LCRs) flanking this locus. Presence of the deletion is associated with variable phenotypic expression, which can include distinctive facial dysmorphologies, congenital heart disease and learning disabilities. An unusually high percentage of individuals with this deletion (25–30%) have been described to develop schizophrenia or schizoaffective disorder. In previous studies, the prevalence of the 22q11 deletion in patients with schizophrenia was found to be approximately 2% in Caucasian adults and 6% in childhood-onset cases. Both these frequencies represent a dramatic increase from the prevalence of the deletion in the general population. In this study, we investigate the occurrence of the 22q11 deletion in an independent sample of schizophrenic patients of Afrikaner origin. We first ascertained a sample of 85 patients who meet full diagnostic criteria for schizophrenia for presence of two or more of the clinical features associated with presence of the 22q11 deletion. A group of six patients (7%) met these criteria. This group was subjected to fluorescent in situ hybridization (FISH) and presence of the 22q11 deletion was confirmed for two subjects. Our study therefore confirms the previously reported rate of 2% frequency of the 22q11 deletion in adult schizophrenic patients and provides a two-stage screening protocol to identify these patients. © 2004 Wiley-Liss, Inc.