Association of dengue virus infection susceptibility with polymorphisms of 2'-5'-oligoadenylate synthetase genes: a case-control study.

Oligoadenylate synthetases play an important role in the immune response against dengue virus. Single nucleotide polymorphisms in the oligoadenylate synthetases genes are known to affect oligoadenylate synthetases activity and are associated with outcome of viral infections. Polymorphisms in the OAS1 SNPs (rs1131454), OAS2 SNPs (rs1293762, rs15895 and rs1732778) and OAS3 SNPs (rs2285932 and rs2072136) genes were studied using PCR followed by restriction fragment length polymorphism methods in 30 patients for dengue infection and 40 control group who have no documented evidence of symptomatic dengue. An increase in the frequency of OAS2 gene rs1293762 SNP G/T heterozygotes (p=0.012), decrease in the frequency of SNP G/G homozygotes (p=0.005) and decrease in the frequency of OAS2 gene rs1732778 SNP G/G homozygotes (p=0.000017) and A/A homozygotes (p=0.0000012) were observed among the dengue patients compared with control group. Our results suggest that OAS2 haplotypes are associated with differential susceptibility to clinical outcomes of dengue virus infection.