Abstract
Objective: Schizophrenia is an invalidating disorder with a clear hereditary component. To date, multiple genetic syndromes and chromosomal aberrations are shown to be associated with schizophrenia-like psychoses. With modern techniques, such as microarray (i.e. array-basedCGH), chromosomes can be investigated at increasingly high resolutions for the presence of microdeletions and/or microduplications. These so-called copy number variations (CNVs) are estimated to be present in up to 3 % of patients with schizophrenia. This study aimed at determining the value of routine screening for CNVs in patients with schizophrenia-spectrum disorders.
Methods: Eighty patients with schizophrenia-spectrum disorders according to ICD-10 were investigated for the presence of CNVs (250 k SNP array, Affymetrix 5.0). Diagnoses were established using the CASH. Psychopathological profiles and symptom severity were measured by means of PANSS and CGI. Of each patient, 3 pictures were taken and evaluated by a clinical geneticist. In case of a proven CNV, the patient was referred to the geneticist for further examination.
Literature was searched on the occurrence of CNVs in schizophrenia patients in general and on the specific CNVs detected in the patients in this study.
Results: In three out of 80 patients a CNV was demonstrated. In one patient a ‘loss’ on chromosome 1q21.1 was found, and in two patients ‘gains’ in respectively 1p13.3 and 7q11.2 were detected. No literature was found on associations between either of these CNVs and schizophrenia-spectrum disorders. For several reasons, in none of the patients the parents could be investigated. Clinical implications of the detected aberrations therefore remained unclear.
Conclusion: Presently, routine screening for CNVs in patients with schizophrenia-spectrum disorders does provide additional diagnostic signifiance. Supplementary molecular genetic evaluation should be reserved for patients in which, besides psychiatric symptomatology, other signs and symptoms are present, especially intellectual disability, dysmorphisms and/or congenital abnormalities.
