Chromosomal microarray analysis-a routine clinical genetic test for patients with schizophrenia.

11 Apr 2019

Aetiological diagnosis for patients with schizophrenia was long thought to be impossible. However, genomic abnormalities with clear causal relevance can now be identified in a consistent minority of cases using chromosomal microarray analysis (CMA; also known as array Comparative Genomic Hybridization or array-CGH). Analogous to a karyotype but with dramatically improved genome-wide resolution, CMA can inform diagnosis and clinical management by identifying sub-microscopic segments of missing (deleted) or additional (duplicated) chromosomal material known as copy number variants (CNVs). CMA is sensitive, reliable, and widely available in clinical laboratories around the world, including major medical centres in the developing world. Costs are competitive with other investigations such as neuroimaging. CMA is now a standard first-line diagnostic test for intellectual disability and autism where 10-20% of affected individuals have a clinically-relevant deletion or duplication (1). Widespread application of CMA testing in these populations has increased confidence in diagnostic interpretation, enhanced the prognostic evidence base, and facilitated research progress (2). In our view, the time has come to translate replicated research findings with proven clinical utility into routine diagnostic practice for patients with schizophrenia.