Rapid identification of YVDD mutants of hepatitis B virus using smart amplification process with competition probe

Accurate and timely detection of drug-associated viral mutants is important during antiviral therapy. Combining Smart Amplification Process (SMAP) with competition probe, an assay specifically designed to detect point mutation at codon 204 of the hepatitis B virus (HBV) polymerase gene was developed. This assay was sensitive to detect 20 copies of mutant/reaction and recognize as little as 1% of minor mutants in the viral population. The comparison of direct sequencing and SMAP method on 35 clinical specimens showed the concordance in 88% of the cases. This method provides an efficient alternative for rapid identification of HBV mutation associated with lamivudine resistance.