title: [Microsatellite polymorphisms at the TNF locus in Hubei Han population].
abstract: OBJECTIVE
  To investigate the distribution of tumor necrosis factor(TNF) microsatellite polymorphisms in Chinese.
  
  
  METHODS
  DNA was extracted from 164 unrelated healthy individuals' EDTA-blood. TNF microsatellite alleles were typed using PCR technique followed by high voltage denaturing PAGE with silver staining at the same time the PCR products were cloned and sequenced.
  
  
  RESULTS
  Thirteen alleles and forty kinds of genotypes were detected at the TNFa locus; two alleles and three kinds of genotypes at the TNFa locus. The polymorphism information contents (PIC) were 0.80 and 0.28 respectively no deviation from Hardy-Weinberg equilibrium was observed. Statistical analysis showed that the distribution of TNFa allele frequencies in Chinese Han population was significantly different from that in European Caucasian or in Japanese P<0.01. The result of sequencing revealed that the copy number of dinucleiotide repeats within the same TNF allele was not consistent with that in the reports from western countries.
  
  
  CONCLUSIONS
  There exists ethnic difference in the distribution of TNFa allele. Further investigations will be necessary to define more accurately and clearly the TNFa alleles.
authors.affiliation: Gastroenterology Department, Zhejiang Provincial People's Hospital, Hangzhou, Zhejiang, 310014 P.R.China. feibaoying6924@163.net
authors.forename: B
authors.initials: B
authors.lastname: Fei
authors.forename: C
authors.initials: C
authors.lastname: Deng
authors.forename: B
authors.initials: B
authors.lastname: Xia
mesh_terms: D000483:Alleles; D001483:Base Sequence; D002681:China; D004247:DNA / Q000737:chemistry / Q000235:genetics; D004252:DNA Mutational Analysis; D005787:Gene Frequency; D005838:Genotype; D018895:Microsatellite Repeats / Q000235:genetics*; D008969:Molecular Sequence Data; D011110:Polymorphism, Genetic; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics*
chemical_list: D014409:Tumor Necrosis Factor-alpha; D004247:DNA