Positive and Negative Symptoms of Schizophrenia and Polymorphic Variants of the TCF4 Gene: Pilot Associative Study

TL;DR

This study explores how genetic variations in the TCF4 gene may influence the symptoms of schizophrenia in a Caucasian population from Siberia.

Contribution

The study identifies new associations between TCF4 gene variants and symptom types in schizophrenia within a Siberian Caucasian population.

Findings

The AA genotype and A allele of rs2958182 and rs9636107 are linked to a predisposition for negative symptoms.

The TT genotype and T allele of rs2958182 and G allele of rs9636107 are more common in patients with positive symptoms.

These associations were observed for the first time in the Siberian Caucasian population.

Abstract

The role of the genetic component in the development of schizophrenia and the formation of its clinical heterogeneity has been proven. To conduct a pilot associative analysis between positive and negative schizophrenia symptoms and polymorphic variants of the Transcription Factor 4 (TCF4) gene. The study included 373 patients with schizophrenia of Caucasian ethnicity, who underwent a comprehensive clinical examination, and a control group consisted of 194 mentally and somatically healthy individuals. Genotyping of three polymorphic variants of the TCF4 gene was carried out in the studied samples (rs2958182, rs8766, and rs9636107). Statistical analysis of the results was performed using Statistica for Windows V.12.0. Association analysis in SNPs was conducted using the chi-square criterion and Bonferroni correction. Groups of schizophrenia patients and healthy individuals were compared for selected TCF4 gene polymorphisms. No statistically significant differences in genotype and allele frequencies were found. The AA genotype and the A allele of the rs2958182 polymorphic variant, as well as the A allele of the rs9636107 polymorphic variant, had an effect predisposing to the predominance of negative symptoms. The TT genotype and the T allele of the rs2958182 polymorphic variant, as well as the G allele of the rs9636107 polymorphic variant, were statistically significantly more common among patients with leading positive symptoms. As a result of the study, associations of the polymorphic variant TCF4 rs2958182 and TCF4 rs9636107 with the leading symptoms of schizophrenia were discovered for the first time in Caucasian populations of the Siberian region. The obtained data confirm the contribution of the genetic component to the formation of clinical heterogeneity of schizophrenia and open up prospects for further search for genetic markers in order to prevent an unfavorable outcome of the disease.