Single nucleotide polymorphisms in the coding regions of human CXC-chemokine receptors CXCR1, CXCR2 and CXCR3

Chemokines and their receptors have critical roles in inflammatory and immunological responses, and thus their genetic contribution to various human disorders needs investigation. In this study, systematic variation screening of the entire coding regions of CXCR1 (IL8RA), CXCR2 (IL8RB) and CXCR3 was carried out, using genomic DNA from a large number of Japanese healthy individuals and patients with rheumatic diseases. In addition to the previously reported variations in CXCR1 and in CXCR2, two non-synonymous, two synonymous substitutions and one nonsense mutation of CXCR1, one non-synonymous and two synonymous substitutions of CXCR2, two non-synonymous substitutions of CXCR3 were newly identified. The common single nucleotide polymorphisms (SNPs) at CXCR1 codon 827 and CXCR2 codon 786 were in strong linkage disequilibrium. In addition, familial analysis indicated that human CXCR3 is located on chromosome X. No significant association was observed between the variations and the tested rheumatic diseases. However, CXCR variations identified in this study will provide valuable information for the future studies in medical sciences as well as in human genetics.