Genetic Variants of Interleukin-10 Gene Promoter are Associated with Schizophrenia in Saudi Patients: A Case-Control Study

BACKGROUND: Interleukin-10 (IL-10) gene is considered as a potential candidate gene in schizophrenia association studies. The polymorphisms on IL-10 gene have been reported to be linked with susceptibility to the development of schizophrenia within consistent results. AIMS: The aim of this case-control study was to examine whether the -1082A/G, -819T/C, and -592A/C polymorphisms in IL-10 gene are implicated in schizophrenia development in the Saudi population. MATERIALS AND METHODS: Molecular genotyping of IL-10 gene polymorphisms was performed to analyze the genotypes and alleles distribution of three single-nucleotide polymorphisms (SNPs) in patients (n = 181) and healthy individuals as control group (n = 211). RESULTS: The frequencies of GA genotype at -1082, and CC genotype at positions -592 and -819 were significantly higher in schizophrenia patients compared to healthy subjects suggesting that GA, CC, and CC genotypes are susceptible to schizophrenia. The ACC haplotype known to be associated with intermediate production of IL-10 are more prevalent in our schizophrenia patients. On the other hand, genotypes -1082 GG, -819 CT, and -592 CA of IL-10 were more prevalent in healthy controls suggesting protective effects of GA, CT, and CA genotypes against schizophrenia. There was no significant association of IL-10 polymorphisms with sex or positive or negative symptoms of schizophrenia. CONCLUSION: This study indicates that the IL-10 gene polymorphisms play a significant role in the etiology of schizophrenia in Saudi Arabians patients.