To study hepatitis B virus (HBV) genotype distribution and mutation patterns of the P region of HBV gene in Linfen.

Realtime quantitative PCR based on fluorescence probe was utilized to detect the genotypes of HBV epidemic strains in Linfen; and the P region of HBV that isolated from 40 patients with chronic HBV infection and with antiviral treatment was sequenced. The most common P area resistance gene mutation sites (rt169-173-180-181-184-202- 204-207-213-214-215-229-233-236-237-238-250) were analyzed.

Of the HBV strains isolated from 272 patients with chronic hepatitis B, 256 were C genotype (94.1%) and 16 were of B genotype (5.9%), There was no B+C genotype and other genotypes. Compared with B genotype, the DNA quantification value of C genotype in clinical specimens was higher(t=6.83, P<0.05); but there was no significant difference about the distribution of B/C genotype in the hepatocirrhosis and chronic hepatitis B groups (χ²=0.067, P>0.05). Among 40 cases, HBV P area gene sequence was successful determinated. There were 2 rtM204V mutations, 2 rtM204I mutations, and 2 rtN238S mutations. All cases of gene mutation were single locus mutation and the mutation rate was 15.0% (6/40).

Genotype C is the dominant genotype of HBV in Linfen and only single locus mutations of the P region are detected in this study.