title: Simultaneous detection of precore/basal core promoter mutations in hepatitis B virus using arrayed primer extension.
abstract: BACKGROUND
  Hepatitis B is a major disease that causes serious public health problems worldwide. The loss of HBeAg expression due to point mutations or single nucleotide polymorphisms (SNPs) in the precore/basal core promoter region of the hepatitis B virus (HBV) is associated with hepatocellular cirrhosis and carcinoma. Simultaneous screening for these mutations is strongly advocated for monitoring disease development in HBV-infected patients. The aim of this study is to apply arrayed primer extension (APEX) for the detection of HBV SNPs at the precore/basal core promoter.
  
  
  RESULTS
  We optimized APEX for simultaneous detection of eight potential sites of SNPs in the precore/basal core promoter region of HBV. The precore/basal core promoter regions of HBV from 36 HBV-infected patients were amplified by PCR. After purification and DNA fragmentation, the short, single-stranded HBV DNA fragments were allowed to hybridize with the oligonucleotides corresponding to the sites of SNPs immobilized on glass slides, followed by incorporation of different fluorescently labeled dideoxynucleotides. This allows fast and unequivocal discrimination between wild-type and mutant genotypes with high dideoxy-nucleotide incorporation efficiency, sensitivity, and specificity. The coexistence of both genotypes was also detected; this was undetected by DNA sequencing.
  
  
  CONCLUSIONS
  The simultaneous detection of SNPs in HBV precore/basal core promoter by APEX enables large-scale diagnostic analysis, which can be extended to the whole HBV genome.
authors: Research and Development Division, School of Chinese Medicine, Hong Kong Baptist University, Hong Kong.
authors: Wai-Yan
authors: WY
authors: Ha
authors: Chi-Chiu
authors: CC
authors: Lau
authors: Patrick Y K
authors: PY
authors: Yue
authors: Kaman K M
authors: KK
authors: Hung
authors: Kelvin
authors: K
authors: Chan
authors: Siu-Hon
authors: SH
authors: Chui
authors: Albert K K
authors: AK
authors: Chui
authors: Wing-Cheong
authors: WC
authors: Yam
authors: Ricky N S
authors: RN
authors: Wong