title: [The prevalence of hepatitis B virus precore mutant isolated from asymptomatic carriers in Guangxi].
abstract: OBJECTIVE
  In order to understand the prevalence of hepatitis B virus (HBV) precore mutants isolated from asymtomatic carriers in Guangxi.
  
  
  METHODS
  Nested polymerase chain reaction (nPCR) was used for amplification of HBV DNA precore in 77 carrier sera, followed by HBV DNA nPCR products sequencing using direct sequencing.
  
  
  RESULTS
  50.7% of 77 carriers was positive for HBV DNA with a prevalence of mutants 22.1% (17/77). HBV DNA positive rate in the southern part of the autonomous region was 55.6% (20/36). Six of them were mutants, counting for 30%. The common mutation in the southern part was seen T-->C at nt1858 while nt1896 stop mutation was discovered in one sample only, which was accompanied by point mutation at nt1837 (A-->G). HBV DNA positive rate in the northern part was 46.3% (19/41) with 11 of them were mutants, counting for 57.9%. The common mutation in that area stopped at nt1896. Among samples with stopped mutation, 4 samples had mutation at nt1846 (A-->T), 2 samples at nt1862 (G-->T). Both mutation at nt1856 (C-->T) and nt1858 (T-->C) could be seen in sample 734.
  
  
  CONCLUSIONS
  The prevalence of HBV precore mutant in asymptomatic carriers in Guangxi was at the average level in China. Further study is needed to determine the difference between the southern and the northern part of the region in the common type of mutation exists.
authors.affiliation: Centre for Diseases Control of Guangxi Zhuang Autonomous Region, Nanning 530021, China.
authors.forename: Zhongliao
authors.initials: Z
authors.lastname: Fang
authors.forename: Hui
authors.initials: H
authors.lastname: Zhuang
authors.forename: Jinye
authors.initials: J
authors.lastname: Yang
authors.forename: Xianmin
authors.initials: X
authors.lastname: Ge
authors.forename: Xueyan
authors.initials: X
authors.lastname: Wang
authors.forename: Jian
authors.initials: J
authors.lastname: Gong
authors.forename: Rongcheng
authors.initials: R
authors.lastname: Li
authors.forename: Roger
authors.initials: R
authors.lastname: Ling
authors.forename: Tim J
authors.initials: TJ
authors.lastname: Harrison
mesh_terms: D001483:Base Sequence; D002353:Carrier State / Q000821:virology*; D004279:DNA, Viral / Q000737:chemistry; D006515:Hepatitis B virus / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D009154:Mutation; D016133:Polymerase Chain Reaction
chemical_list: D004279:DNA, Viral