[Pharmacogenetic aspects of the dopaminergic system in clozapine pharmacodynamics]

A systematic review of association studies on the role of single nucleotide variants (SNVs) of the dopaminergic system genes on the effectiveness of clozapine in schizophrenia has been perfromed. A search of literature was conducted in PubMed, MedLine, Web of Science Core Collection (Clarivate Analytics), Web of Science, Russian Science Citation Index, Scopus, Scientific Research, Google Scholar, Oxford Press, e-Library from 1995-2019. Association studies of 53 SNPs of genes encoding dopamine receptor isoforms (DRD1), dopamine transporter (SCL6A3) and catechol-O- methyltransferase (COMT), and the nature of their association with the therapeutic response to clozapine were analyzed. The results of SNPs studies of DRD1 and COMT genes are the most controversial. This can be explained by the heterogeneity of the samples and the lack of standardization of methods for evaluating the effectiveness of treatment in the context of association studies. The clear population specificity of the association of some SNPs of DRD1, DRD2 and DRD3 genes with the response to clozapine therapy has been shown. Most of the identified associations are haplotype specific. The obtained regularities of the effect of SNPs of dopaminergic system genes on the effectiveness of clozapine therapy should be considered in an individual approach to treatment of schizophrenia.