title: X gene and precore region mutations in the hepatitis B virus genome in persons positive for antibody to hepatitis B e antigen: comparison between asymptomatic "healthy" carriers and patients with severe chronic active hepatitis.
abstract: Hepatitis B virus (HBV) carriers with antibody to hepatitis e antigen comprise asymptomatic carriers (ASCs), who have low replication levels of HBV, and patients with chronic active hepatitis (CAH), who have high levels of viral replication. To investigate whether defects in the X protein might be responsible for this difference in the level of viral replication, nucleotide sequences of X and precore gene regions in serum HBV were analyzed in 19 ASCs and 9 CAH patients. All patients had a point mutation creating a stop codon in the precore region. Seventeen ASCs (87.3%) had identical mutations consisting of 4 noncontiguous 1-bp deletions or an 8-bp deletion, both of which truncate the normal X protein, whereas no CAH patient had an X gene mutation (P < .001). Thus, deletion of the X protein might be responsible for the low levels of viral replication in ASCs.
authors.affiliation: 2nd Department of Internal Medicine, Shimane Medical University, Izumo-Shi, Japan.
authors.forename: R
authors.initials: R
authors.lastname: Fukuda
authors.forename: X T
authors.initials: XT
authors.lastname: Nguyen
authors.forename: N
authors.initials: N
authors.lastname: Ishimura
authors.forename: S
authors.initials: S
authors.lastname: Ishihara
authors.forename: A
authors.initials: A
authors.lastname: Chowdhury
authors.forename: N
authors.initials: N
authors.lastname: Kohge
authors.forename: S
authors.initials: S
authors.lastname: Akagi
authors.forename: M
authors.initials: M
authors.lastname: Watanabe
authors.forename: S
authors.initials: S
authors.lastname: Fukumoto
mesh_terms: D000328:Adult; D000368:Aged; D000595:Amino Acid Sequence; D001483:Base Sequence; D002353:Carrier State / Q000276:immunology / Q000821:virology*; D003062:Codon / Q000235:genetics; D017931:DNA Primers; D004279:DNA, Viral / Q000032:analysis / Q000235:genetics; D005260:Female; D016679:Genome, Viral; D006509:Hepatitis B / Q000276:immunology / Q000821:virology*; D006510:Hepatitis B Antibodies / Q000097:blood*; D006511:Hepatitis B Antigens / Q000235:genetics; D006513:Hepatitis B e Antigens / Q000276:immunology*; D006515:Hepatitis B virus / Q000235:genetics* / Q000276:immunology / Q000302:isolation & purification*; D006801:Humans; D008099:Liver / Q000821:virology*; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D017354:Point Mutation; D016133:Polymerase Chain Reaction; D015534:Trans-Activators / Q000235:genetics*; D054334:Viral Regulatory and Accessory Proteins
chemical_list: D003062:Codon; D017931:DNA Primers; D004279:DNA, Viral; D006510:Hepatitis B Antibodies; D006511:Hepatitis B Antigens; D006513:Hepatitis B e Antigens; D015534:Trans-Activators; D054334:Viral Regulatory and Accessory Proteins; C057628:hepatitis B virus X protein