title: Surface gene mutations of hepatitis B virus among high-risk patients with occult hepatitis B virus infection.
abstract: Surface gene mutants of hepatitis B virus (HBV) have been reported in a variety of patient groups. Because of limited data regarding these mutations in patients with occult HBV infections; we aimed to determine these mutations among high-risk patients with occult HBV infection. The presence of HBV-DNA was determined in patients with isolated anti-HBc by real-time polymerase chain reaction (PCR). Then, surface gene region was amplified by nested PCR and mutations were analyzed after sequencing. The mutations that resulted in nonfunctional hepatitis B surface antigen (HBsAg) were insertion of single nucleotide in 2 cases, which causes frameshift and single-nucleotide replacement, and premature stop codons at Leu15 and Gly10 in the other 2 cases. Amino acid substitution at amino acid position 207(S207N) was found in the other isolates. Our study suggested that "a" region mutations did not play a major role in HBsAg detection, and other genetic and nongenetic factors may be responsible for failure to detect HBsAg by routine laboratory tests.
authors.affiliation: Tehran University of Medical Sciences, Tehran 14155, Iran. rhamkar@sina.tums.ac.ir
authors.forename: Rasool
authors.initials: R
authors.lastname: Hamkar
authors.forename: Arezoo
authors.initials: A
authors.lastname: Aghakhani
authors.forename: Safyeh
authors.initials: S
authors.lastname: Soufian
authors.forename: Mohammad
authors.initials: M
authors.lastname: Banifazl
authors.forename: Nastaran
authors.initials: N
authors.lastname: Ghavami
authors.forename: Mahsa
authors.initials: M
authors.lastname: Nadri
authors.forename: Masoomeh
authors.initials: M
authors.lastname: Sofian
authors.forename: Farrokhlagha
authors.initials: F
authors.lastname: Ahmadi
authors.forename: Effat
authors.initials: E
authors.lastname: Razeghi
authors.forename: Ali
authors.initials: A
authors.lastname: Eslamifar
authors.forename: Amitis
authors.initials: A
authors.lastname: Ramezani
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019943:Amino Acid Substitution; D001483:Base Sequence; D018389:Codon, Nonsense; D003430:Cross-Sectional Studies; D005260:Female; D015658:HIV Infections / Q000821:virology; D006509:Hepatitis B / Q000821:virology*; D006514:Hepatitis B Surface Antigens / Q000235:genetics*; D006515:Hepatitis B virus / Q000235:genetics* / Q000276:immunology; D006801:Humans; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D009154:Mutation; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D016415:Sequence Alignment
chemical_list: D018389:Codon, Nonsense; D006514:Hepatitis B Surface Antigens