A nonsynonymous single nucleotide polymorphism (Asp299Gly) in the Toll-like receptor-4 (TLR-4) gene affects the responsiveness to lipopolysaccharide in humans. To analyze this important polymorphism more efficiently, we developed a simple polymerase chain reaction (PCR) restriction length fragment polymorphism (RFLP) assay and examined the Asp299Gly allele frequency in a Japanese population. The PCR primer was designed with 1- or 2-bp mismatches, creating the recognition sequence for restriction enzyme BsaBI or BstXI, allowing RFLP analysis of the digested products. Genotyping was carried out with this assay for 275 DNA specimens from 107 healthy volunteers and 168 patients with various diseases, including ulcerative colitis (n = 86). The Asp299Gly allele of the TLR-4 gene was not detected in any of the specimens, suggesting that it is very rare in Japanese.
Copyright 2002 Wiley-Liss, Inc.