Single-Nucleotide Polymorphisms and Haplotype Analysis in β-Defensin Genes in Different Ethnic Populations

β-Defensins are cationic antimicrobial peptides expressed by epithelial cells and exhibit antibacterial, antifungal, and antiviral properties. The defensins are part of the innate host defense network and may have a significant protective role in the oral cavity and other mucosa. Defects or alteration in expression of the β-defensins may be associated with susceptibility to infection and mucosal disorders. We examined the occurrence of single-nucleotide polymorphisms (SNPs) in the human β-defensin genes DEFB1 and DEFB2 encoding human β-defensin-1 and -2 (hBD-1, hBD-2), respectively, in five ethnic populations and defined haplotypes in these populations. Fifteen SNPs were identified in both DEFB1 and DEFB2. Coding region SNPs were found in very low frequency in both genes. One nonsynonymous DEFB1 SNP, G1654A (Val → Ile), and one nonsynonymous DEFB2 SNP, T2312A (Leu → His), were identified. Seven sites in each gene exhibited statistically significant differences in frequency between ethnic groups, with the ...