Genetic Polymorphism of Toll-Like Receptor 4 Thr399Ile Variant in Iraqi Kurdish Population: Sulaymaniyah Province

Abstract

Toll-like receptors (TLRs), encoded by innate immune genes, functions to detect microbial ligands. Studies found that polymorphisms in TLR genes among populations are associated with diseases. Among the classes of TLRs, TLR-4 is important for exploring bacterial lipopolysaccharide. TLR-4 Thre399Ile is one of the most important non-synonymous variant which varies among different background populations. Kurds, an ethnic population descended mainly from indigenous inhabitants of Zagros mountain survived for millennia, with nearly 40 million populations, are distributed in Iraq, Turkey, Iran and Syria. There are no studies on genetic variations of TLR4 in this population, particularly in Iraqi Kurdistan. The aim of this study is to find the percentage frequency of TLR4 Thr399Ile variant in Kurdish populations in Iraq, particularly in Sulaymaniyah province. The percentage of single nucleotide polymorphisms (SNPs) of the TLR4 gene was determined by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP). The results showed that the heterozygous variant of TLR4 Thr399Ile is 7.1% (n=85) in Sulaymaniyah populations. However, no homozygous mutant variant was found; this suggests that it is either absent or seldom among Kurds in the region. This study emphasises the perceptiveness of the TLR SNP in Sulaymaniyah populations that recommends future study for linking this genetic variation with both infectious and immunological diseases, in addition to historical, anthropological and archaeological studies.

Keywords

• toll- like receptor 4
• polymorphism
• snps
• iraq
• kurdistan
• population