Hardy–Weinberg Disequilibrium of the IL-18 C−607A SNP Suggesting Selective Advantage of Heterozygotes

Abstract

Interleukin-18 (IL-18) plays a key role in autoimmune, inflammatory, and infectious diseases. The IL-18 gene contains a C to A single nucleotide polymorphism (SNP) at position -607 (C-607A) within the promoter region, which was found to affect the promoter activity and subsequently the protein level of IL-18. We investigated this SNP in a group of healthy Singaporeans and found that CA was the most common genotype and the C allele was more prevalent than the A allele, which was not always the case in other ethnic groups. In addition, Singaporean Chinese were significantly different from Singaporean Indians in both allelic and genotypic distributions. Furthermore, significant deviations from Hardy-Weinberg equilibrium of this SNP were found in all three ethnic groups studied (Chinese, Indians, and Malays) and also in other published literature, suggesting that heterozygotes of this IL-18 C-607A SNP may have certain selective advantages.

Correlation of single nucleotide polymorphisms in the AGT gene with susceptibility to systemic lupus erythematosus in Northeast China

“…HWE genetic equilibrium is a vital principle in population genetics. The subsequent research can only be deemed convincing if the target locus satisfies the HWE genetic equilibrium test and can be stably inherited within the target population (Schrodi et al, 2015; Chen & Gan, 2012).…”

“…This research necessitates the stable inheritance of the target SNP in both healthy populations and those with SLE prior to the following investigation. This is because SNP that cannot be stably inherited in the target population will introduce greater variability into the results of subsequent studies and therefore reduce the firmness of any conclusions drawn (Chen & Gan, 2012). Therefore, we excluded the rs699 from the subsequent study.…”