Further evidence of the role of microRNA in schizophrenia: a case report.

According to the neurodevelopmental hypothesis of schizophrenia, genetic predisposing factors cause abnormalities in neural functions, leading to the disease. A 2-year follow-up of a young woman with schizophrenia is presented. Karyotype, Affymetrix CytoScanTM 750K SNP array, and optical genome mapping ultra-high molecular weight were carried out. The case presented a severe and resistant to treatment schizophrenia. A 404 kbp microduplication in 2q13 (chr2 : 112088944-112492811; Hg19) was revealed, which includes an only gene (MIR4435-2HG, OMIM 617144). The Positive and Negative Syndrome Scale of Schizophrenia questionnaire showed a moderate improvement after 2 years, but functioning was still poor. The presented case had a microduplication of copy number variants at 2q13, previously linked to schizophrenia, but it only involved one gene, encoding a microRNA, which regulates the expression of candidate genes associated to neurodevelopment. This case provides further evidence of the importance of microRNA in the pathogenesis of schizophrenia.