[Detection and analysis of the new kind of G743C and G743A point mutation of HBV P gene in hepatitis B virus infected patients resistant to lamivudine].
OBJECTIVE
To explore the point mutation in hepatitis B virus polymerase (HBV P) gene in HBV-infected patients resistant to lamivudine.


METHODS
HBV P gene was amplified by PCR and the products was sequenced to analyze the YMDD mutation. Then the variants were detected by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) with the following restriction enzymes: Fok I, Ssp I, Alw441 and were separated by 8.0% polyacrylamide gel electrophoresis.


RESULTS
Comparing with the sequences of standard HBV genome, there were 16 patients with G743C mutation and 1 patient with G743A mutation, and the codon ATG turned to ATC and ATA, YMDD motif changed into YIDD. But this kind of YIDD mutation was not proved by PCR-RFLP assay in the 17 patients.


CONCLUSIONS
The G743C and G743A mutations in HBV P gene, resulting in YMDD motif changed into YIDD, are detected only by direct sequencing, not by PCR-RFLP. The new kind of G743C and G743A point mutations in HBV P gene is important for the detection of HBV P gene YMDD mutation.
Institute of Infectious Diseases, First Affiliated Hospital, Medical College of Zhejiang University, Hangzhou 310003, China.
Xiao-ping
XP
Pan
Jian-er
JE
Wo
Zhi
Z
Chen
Feng
F
Chen
Wei-feng
WF
Liang
Ke-zhou
KZ
Liu
D000328:Adult; D020816:Amino Acid Motifs / Q000235:genetics; D000998:Antiviral Agents / Q000494:pharmacology / Q000627:therapeutic use; D003001:Cloning, Molecular; D017931:DNA Primers / Q000235:genetics; D004279:DNA, Viral / Q000097:blood / Q000235:genetics; D004259:DNA-Directed DNA Polymerase / Q000235:genetics; D024882:Drug Resistance, Viral / Q000235:genetics*; D005260:Female; D015684:Gene Products, pol / Q000235:genetics; D006515:Hepatitis B virus / Q000235:genetics*; D019694:Hepatitis B, Chronic / Q000188:drug therapy* / Q000821:virology; D006801:Humans; D019259:Lamivudine / Q000494:pharmacology / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D017354:Point Mutation
D000998:Antiviral Agents; D017931:DNA Primers; D004279:DNA, Viral; D015684:Gene Products, pol; C066027:P protein, Hepatitis B virus; D019259:Lamivudine; D004259:DNA-Directed DNA Polymerase