Role of rs6313 and rs1799978 variants as pharmacogenomic biomarkers in Greek, Italian and Croatian schizophrenia patients

Introduction Schizophrenia (SZ) is a serious mental disorder that significantly affects patients' quality of life (QoL). Its etiology is still unknown; however, both environmental and genetic factors play important role. Atypical antipsychotics, fight mainly against its psychotic symptoms but can also cause various side effects. Objectives/aims The study was based on a literature review and a meta-analysis which revealed pharmacogenomic biomarkers for the individualization of treatment with atypical antipsychotics. Main aim was to investigate emerging polymorphisms, in Caucasian healthy individuals and schizophrenics. Materials & methods Four hundred and eighty-five schizophrenic patients and 393 matched controls of healthy donors were studied. Patients were of Greek, Italian, Croatian and Slovenian origin. The group of patients was divided into two subgroups; TRS (treatment resistant schizophrenia) and responders in atypical antipsychotics. Genotyping was performed by Sanger sequencing and PCR/BpEI-based method. Results rs6313 and rs1799978 were indicated as potential biomarkers of patients' response on antipsychotics. Experimental results suggest non-correlation of polymorphisms with patients' response to these drugs in Greek, Italian, Croatian and Slovenian populations. Conclusions SZ's etiology is highly complex, however, pharmacogenomic studies can lead to the identification of genetic loci important for disease pathobiology and management as well as patient stratification. Herein, no correlation was evident regarding rs6313 and rs1799978 and drug response in the Caucasian populations studied. Next, sample number will be extended and a more wide cross-population assessment will occur. Knowledge acquired and technology improvement, will lead to a better understanding of the underlying mechanisms, and will subsequently contribute to the improvement of patients' QoL.