Polymorphisms at the TNF locus in Chinese Han population

One hundred sixty-four unrelated healthy individuals from Chinese Han population were investigated in order to define the distribution of eight polymorphic loci within the tumor necrosis factor (TNF) gene cluster and determine their relationship between the high polymorphic microsatellite TNFa, b, d, and other elements. The cloning and sequencing for five microsatellites were simultaneously done. In this study, the distribution of TNF alleles apparently vary from other ethnic groups. A new allele was detected and confirmed. It should be emphasized that a very strong association between TNFd8 and TNFe4 is reported and d8e4 haplotype appears to be specific to the population studied. In addition, five extended haplotypes were established in this population: a6b5cl d8e4TNF308-ITNF-betaNco1-1TNFAspH1-2, a2b1c2d5 e1TNF308-1TNF-betaNco1-2TNFAspH1-2,a1 1b4c1d4e3TNF308-1TNF-betaNco1-2TNFAspH1-1, a10b4c1d4e3TNF308-1TNF-betaNco1-2TNFAspH1-1,and a2b3c1d2e3TNF308-2TNFAspH1-2. Data suggest that important ethnic differences may exist and that it is a necessary initiative for further research. (C) American Society for Histocompatibility and Immunogenetics, 2002. Published by Elsevier Science Inc.