[Full-length sequence of hepatitis B virus isolated from high incidence hepatocellular carcinoma area-Longan county].

OBJECTIVE: To understand full-length sequence of HBV isolated from high incidence hepatocellular carcinoma area-Longan county, Guangxi. METHODS: The nested polymerase chain reaction (nPCR) was used for amplifying the whole HBV DNA in sera of asymptomatic carriers. The products were sequenced by clone sequencing and homological analysis. RESULTS: This isolate contained 3 215 bases. The genotype was C and the serotype was adw. There were 40 point mutations in polymerase gene which made 11 amino acids change. There were 11,2 and 3 point mutations in PreS1, PreS2 and S gene respectively which made 3,1,1, amino acids change. Six point mutations including the double mutations (nt 1762 A to T, 1764 G to A) were found in X gene leading to 4 amino acids change. There were 13 point mutations in C gene which made 2 amino acids change. No mutation was found in a determinant and Pre C. The isolate was quite close to the isolate from Vietnamese in evolution while far from the genotype C isolates from Shanghai, Beijing and Tibet. CONCLUSION: No special sequence was found in the isolate from high incidence hepatocellular carcinoma area, Longan county, Guangxi.