Synonymous and non-synonymous polymorphisms in toll-like receptor 2 (TLR2) gene among complicated measles cases at a tertiary care hospital, Peshawar, Pakistan

OBJECTIVES: To detect single nucleotide polymorphism in toll-like receptor 2 (TLR2) gene in complicated cases of measles, in order to understand the genetic basis of complex human immune responses against measles complications. METHODS: A total of 100 children consisted of 50 measles complicated cases while rest were gender matched disease-free individuals who served as controls for this study. Patient demographic data and clinical information were recorded on a separate pre-designed model form. All exonic regions of TLR2 gene of the patients and control samples were amplified through polymerase chain reaction. Various in-silico mutation verification tools like protein variation effect analyzer, MUPRO, sorting intolerant from tolerant, functional analysis through hidden Markov models, and polymorphism phenotyping v2 to study the effect of novel non-synonymous polymorphism on structure and function of TLR2 protein. RESULTS: Synonymous and novel non-synonymous polymorphisms were identified in measles complicated cases. Among these, rs1816702 was marked to 5 untranslated region section of TLR2 gene, while rs3804099 and rs3804100 were identified in the coding region. Novel non-synonymous polymorphisms were shown in the coding region of TLR2 gene. No significant association was established between the observed genetic polymorphisms and measles complications. However, rs3804100 increased the risk of lower respiratory tract infection. CONCLUSION: The overall impact of novel non-synonymous polymorphism of TLR2 protein structure and functions was neutral and tolerated.