title: Intra-familial evidence of horizontal transmission of hepatitis B virus surface antigen mutant G145R.
abstract: OBJECTIVE
  To provide intra-familial evidence on the horizontal transmission of hepatitis B virus surface antigen (HBsAg) mutant G145R.
  
  
  METHODS
  Serum samples from family members of 10 vaccinated infants who carried this G145R mutant were collected. The presence of the mutant was analysed by polymerase chain reaction (PCR) and sequencing.
  
  
  RESULTS
  The G145R mutant was identified in family members of three of the 10 infants. In family 1, the mutant found initially in child 1 was identified in another child and the father. In families 2 and 3, the G145R mutant detected previously in child 1 was detected in the father. Additional mutations in HBsAg were identified in at least two members in family 1 and 2, suggesting horizontal transmission of the mutant among them. The G145R mutant was found in samples with high levels of neutralizing antibody against HBV (anti-HBs). In addition, liver damage was seen in one G145R carrier infant.
  
  
  CONCLUSIONS
  The G145R mutant could be transmitted horizontally among family members, and this could occur in the presence of high levels of anti-HBs. Improvement of detection system for the G145R and other HBsAg mutant will be needed for their effective control.
authors: Ransome Research Laboratory, Singapore General Hospital, Republic of Singapore.
authors: C J
authors: CJ
authors: Oon
authors: W N
authors: WN
authors: Chen
authors: K S
authors: KS
authors: Goo
authors: K T
authors: KT
authors: Goh
mesh_terms: D018562:Disease Transmission, Infectious; D005192:Family Health; D005260:Female; D006509:Hepatitis B / Q000276:immunology / Q000635:transmission* / Q000821:virology*; D006510:Hepatitis B Antibodies / Q000097:blood; D006514:Hepatitis B Surface Antigens / Q000235:genetics*; D017325:Hepatitis B Vaccines; D006515:Hepatitis B virus / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D007223:Infant; D008297:Male; D009154:Mutation; D009500:Neutralization Tests; D016133:Polymerase Chain Reaction; D014611:Vaccination
chemical_list: D006510:Hepatitis B Antibodies; D006514:Hepatitis B Surface Antigens; D017325:Hepatitis B Vaccines