Functional polymorphism of the myeloperoxidase gene (G-463A) in depressive patients

Objective: Myeloperoxidase (MPO) is an enzyme involved in the production of hypochloric acid as well as other reactive oxygen species. This enzyme plays a significant role in inflammatory processes. In view of the observed associations between depression and such inflammatory processes, as well as of the reports that confirm the presence of oxidative stress in depression, this study was designed to assess the correlation, if any, between the single nucleotide polymorphism G-463A of the MPO gene and the risk of recurrent depressive disorders (DD). Methods: The study was carried out in a group of 149 patients with recurrent DD and 149 healthy control subjects. Genotyping was performed by PCR/restriction fragment length polymorphism. Results: A comparison between healthy controls and depressive patients showed a statistically significant difference in genotype distribution and allele frequency in the studied groups. Genotype distribution and allele frequency did not correlate with clinical variables of the patients. Conclusion: The obtained results of the study allow us to draw a cautious conclusion about the role of the analysed G-463A MPO polymorphism in recurrent DD development, which, however, requires eventual confirmation in further studies.