Genotype–phenotype analysis of paraoxonase 1 (PON1) in schizophrenic patients treated with atypical antipsychotics
Denis Paval 1, Bogdan Nemes 2, Razvan L. Rusu 1, Eleonora Dronca 1*
1Department of Molecular Sciences, Faculty of Medicine, ‘Iuliu Hațieganu’ University of Medicine and Pharmacy, Cluj-Napoca, Romania, 23rd Psychiatry Clinic, Emergency County Hospital, Cluj-Napoca, Romania
Received: October 3, 2016; Revised: December 14, 2016; Accepted: December 16, 2016; Published online: December 16, 2016.
© The Korean College of Neuropsychopharmacology. All rights reserved.

Objective: Recent studies suggest a possible involvement of low paraoxonase 1 (PON1) enzyme activities in the association between schizophrenia, treatment with atypical antipsychotics (AAP) and increased cardiovascular (CVD) risk. In the present study, we aimed at investigating the PON1 status in a group of schizophrenic patients treated with either olanzapine or other antipsychotic, as compared to a group of healthy control participants.
Methods: We assessed the arylesterase (AREase) and paraoxonase (POase) activities of PON1, as well as three common polymorphisms of PON1 gene (Q192R, L55M, -108C>T).
Results: We found significantly lower (–13.3%) AREase activity in schizophrenic patients, along with significantly lower (–18.2%) POase activity in olanzapine–treated patients with QQ genotype. Furthermore, we found a significant difference between groups in L55M polymorphism distribution, whereas Q192R and -108C>T polymorphisms distributions were similar.
Conclusion: We identified the olanzapine–treated patients with QQ genotype as having the lowest PON1 (POase) activity, providing a possible way of identifying schizophrenic patients exposed to the greatest risk of CVD.
Keywords: paraoxonase 1, PON1, polymorphism, atypical antipsychotics, olanzapine, cardiovascular disease