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

• Published in: Biochemical genetics 2012-02, Vol.50 (1-2), p.63-72
• Main Authors: Chen, Chuan Fei, Gan, Yik Yuen
• Format: Article
• Language: English
• Subjects: Asian Continental Ancestry Group - genetics; Biochemistry; Biomedical and Life Sciences; Biomedicine; Ethnic Groups - genetics; Heterozygote; Human Genetics; Humans; Infectious diseases; Interleukin-18 - genetics; Medical Microbiology; Minority & ethnic groups; Models, Genetic; Polymorphism, Single Nucleotide; Singapore - ethnology; Zoology
• ISSN: 0006-2928; 1573-4927
• DOI: 10.1007/s10528-011-9459-z

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.