Polymorphism of KIR2DL4 gene among northern Chinese Han population

Abstract

Objective To investigate the polymorphism of KIR2DL4 gene in northern Chinese Han population. Methods A total of 327 DNA samples were isolated by magnetic beads from unrelated individuals of northern Chinese Han population. The coding sequence (CDS) of KIR2DL4 were amplified using four pairs of KIR2DL4-specific PCR primers developed by our own KIR sequencing-based typing patent, and each exon of KIR2DL4 carried by the four PCR amplicons was then subjected to DNA Sanger sequencing in both directions. The genotype of each sample was assigned using the Assign 4.7 software. Results Among 327 individuals, 8 different kinds of KIR2DL4 alleles were detected, with observed frequencies ranked as KIR2DL4*00102 [77.1%(252/327)], *00501 [35.8%(117/327)], *011 [20.2%(66/327)], *00602 [12.5%(41/327)], *00801 [8.6%(28/327)], *00103 [4.9%(16/327)], *00503 [1.5%(5/327)] and *00504 [0.9%(3/327)]. In this study, the 10A type alleles which can encode a full membrane-bound receptor include 2DL4*00102, *00103, *00501, *00503, *00504 and *00602, whereas the 9A type alleles which produce truncated forms of receptor include 2DL4*00801 and *011. The observed frequencies for 10A and 9A type KIR2DL4 alleles were 97.6% (319/327) and 27.8% (91/327), respectively. The ratio of 10A to 9A type was 3.5: 1. The observed frequencies of KIR2DL4 alleles in northern Chinese Han population showed no significant difference compared with southern Chinese Han population (P>0.05). Conclusion The allelic diversity of KIR2DL4 elucidated in the present study can provide valuable data for KIR-associated disease studies and human evolution.

Keywords

• killer cell immunoglobulin-like receptor
• kir2dl4 gene
• allele
• diversity
• northern chinese han population
• sequence-based typing