The common genetic variants of toll-like receptor and susceptibility to adenoid hypertrophy: A hospital-based cohort study

Abstract

Background/aim: Adenoid hypertrophy (AH) is one of the most frequent pediatric disorders. The aim of this study was to investigate the effects of TLR2-R753Q, TLR4-T399I, and TLR4-D299G polymorphisms in children with AH. Materials and methods: The variants of the TLR gene were determined by restriction fragment length polymorphism (PCR-RFLP) analysis in 60 patients with AH and in 50 healthy children. Data were analyzed with SNPStats and multifactor dimensionality reduction (MDR) software. Results: We found that the presence of the G allele, the AG+GG and AG genotypes at TLR4-D299G, and the GGT haplotype were associated with AH in children (P = 0.013, P = 0.02, P = 0.038, and P = 0.001, respectively). On the contrary, no association was found between TLR2-R753Q and predisposition to AH. The CT genotype at TLR4-T399I showed a sex-specific association with AH, occurring only in boys with allergies (P = 0.0048). In addition, MDR analysis indicated a strong synergy between TLR gene markers contributing to AH. Allergic children with the diplotypes that included minor alleles of TLR4-D299G or TLR4-T399I had about a 4-fold increased risk for AH. Conclusion: Common genetic variants of the gene encoding the TLR4 protein may have differential effects on AH and the presence of sex-specific allergy.