Lack of association of IL-6 (−174 G > C) and TNF-α (−238 G > A) variants with paranoid schizophrenia in Indian Bengalee population

Schizophrenia is a chronic debilitating neuropsychiatric disorder with complex etiopathology. Growing evidence suggests a significant role of chronic low grade inflammation in the pathophysiology of schizophrenia. Multiple immunological, genetic polymorphism and gene expression studies have established crucial roles of certain pro-inflammatory cytokines in the immune-mediated risk of schizophrenia. Although genetic studies suggest some variants within the pro-inflammatory IL-1β, IL-6, and TNF-α genes conferring risk to schizophrenia, the results however have been contradictory in various populations. In the present investigation, promoter SNPs of IL-6 (−174 G > C) and TNF-α (−238 G > A) genes have been studied to evaluate whether these variants contribute to schizophrenia susceptibility in Indian Bengalee population. Genotyping of the above SNPs was done in 100 well characterized and confirmed cases of paranoid schizophrenia and equal number of healthy donors belonging to the same ethnic group by using ABI 3730 Genetic Analyzer. No significant differences in genotype as well as allele frequencies were observed for IL-6 and TNF-α variants between the patient and control groups.

► We have evaluated the association of pro-inflammatory markers in paranoid schizophrenia. ► We have examined sequence variation of the promoter SNP of two pro-inflammatory cytokines, IL-6 and TNF-α gene. ► IL-6 and TNF-α promoter variants do not confer risk of paranoid schizophrenia in Indian Bengalee population.