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Schizophrenia Research and Treatment
Volume 2017 (2017), Article ID 5763094, 8 pages
https://doi.org/10.1155/2017/5763094
Research Article

Interaction Effects of Season of Birth and Cytokine Genes on Schizotypal Traits in the General Population

Mental Health Research Center, Kashirskoe Shosse 34, Moscow 115522, Russia

Correspondence should be addressed to Margarita V. Alfimova; moc.liamg@avomifla.m

Received 15 August 2017; Accepted 13 December 2017; Published 31 December 2017

Academic Editor: Luis San

Copyright © 2017 Margarita V. Alfimova et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Literature suggests that the effect of winter birth on vulnerability to schizophrenia might be mediated by increased expression of proinflammatory cytokines due to prenatal infection and its inadequate regulation by anti-inflammatory factors. As the response of the immune system depends on genotype, this study assessed the interaction effects of cytokine genes and season of birth (SOB) on schizotypy measured with the Schizotypal Personality Questionnaire (SPQ-74). We searched for associations of IL1B rs16944, IL4 rs2243250, and IL-1RN VNTR polymorphisms, SOB, and their interactions with the SPQ-74 total score in a sample of 278 healthy individuals. A significant effect of the IL4 X SOB interaction was found, and . We confirmed this effect using an extended sample of 373 individuals. Homozygotes CC born in winter showed the highest SPQ total score and differed significantly from winter-born T allele carriers, . This difference was demonstrated for cognitive-perceptual and disorganized but not interpersonal dimensions. The findings are consistent with the hypothesis that the cytokine genes by SOB interaction can influence variability of schizotypal traits in the general population. The IL4 T allele appeared to have a protective effect against the development of positive and disorganized schizotypal traits in winter-born individuals.