Identification of a novel 120 bp allele at the TNFd microsatellite locus

Tumor necrosis factor‐α (TNF‐α) is a pro‐inflammatory cytokine mainly secreted by macrophages and T‐cells that play a key role in the pathogenesis of many infectious and inflammatory diseases. The TNF gene cluster is located within the class‐III region of the highly polymorphic major histocompatibility complex on human chromosome 6p21. A cluster of six multiallelic microsatellites has been identified in the TNF region, named TNF a–e. TNFb, TNFc, TNFd, and TNFe are (GA)n repeats, whereas TNFa and TNFf are (GT)n and (CA)n repeats, respectively. The TNFd microsatellite locus maps 8–10 kb centromeric to the TNF‐α gene, downstream to the TNF‐β gene.