title: S gene mutations of HBV in children with HBV-associated glomerulonephritis.
abstract: BACKGROUND
  Hepatitis B virus-associated glomerulonephritis (HBV-GN) is a kind of immune complex-induced glomerulonephritis. The present study was designed to determine whether mutation of Hepatitis B virus (HBV) S gene is associated with glomerulonephritis in Chinese children.
  
  
  METHODS
  Total 53 subjects, including 30 HBV-GN, 5 nephrosis with HBV carriers (control group 1), and 18 HBV carriers (control group 2) were included in this study. Polymerase chain reaction (PCR) was used to detect the HBV-GN S gene mutation.
  
  
  RESULTS
  (1) The serotype of HBV was adw in the majority (52/53) of subjects, and was adr in only 1 subject in the control group 2; (2) the genotype of HBV was the type B in 51 subjects, the type E in 1 HBV-GN child, and the type C in 1 HBV carrier; (3) Seventeen point mutations in the S gene of HBV were identified in 21 of 30 (70%) HBV-GN patients. Among them, 16 of 21 (76.2%) mutations may cause amino acid substitutions of the HBV proteins, which occur predominantly (11/16 mutations) at threonine, serine or tyrosine phosphorylation sites of mitogen-activated protein kinase (MAPK) or protein tyrosine kinase (PTK). (4) In addition, single nucleotide mutations without amino acid substitutions (same sense mutation) were found in 2 subjects in each control group and 5 subjects in HBV-GN group.
  
  
  CONCLUSIONS
  HBV S gene mutations and the subsequent amino acid substitutions in HBV proteins were found in most children with HBV-GN, suggesting that these mutations may play an important role in the pathogenesis of HBV-GN.
authors.affiliation: Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, People's Republic of China.
authors.forename: Hongzhu
authors.initials: H
authors.lastname: Lu
authors.forename: Hui
authors.initials: H
authors.lastname: Zhu
authors.forename: Jianhua
authors.initials: J
authors.lastname: Zhou
mesh_terms: D001483:Base Sequence; D002648:Child; D002675:Child, Preschool; D005260:Female; D005838:Genotype; D005921:Glomerulonephritis / Q000209:etiology / Q000821:virology*; D006509:Hepatitis B / Q000150:complications*; D006514:Hepatitis B Surface Antigens / Q000235:genetics*; D006515:Hepatitis B virus / Q000145:classification / Q000235:genetics*; D006801:Humans; D008297:Male; D009154:Mutation; D012703:Serotyping
chemical_list: D006514:Hepatitis B Surface Antigens