OBJECTIVEGene chip technology was set up to quickly and accurately detect and identify the HBV P gene YMDD motif mutation during the chronic hepatitis treated with lamivudine.

METHODSDNA microarrays were prepared by spotting fluorescence labeled probes of target genes onto specially lattice glass slides with robotics. The serum samples from 30 patients with hepatitis B after 68-week treatment with lamivudine were detected double-blind by gene chips and by nucleotide sequences assay technique to identify the rate of emergence of HBV P gene YMDD motif mutation.

RESULTSTwenty-one patients were found HBV P gene YMDD motif mutation by the gene chips including 11 cases with YVDD and 10 cases with YIDD motif mutation. By direct sequencing of the PCR products, 11 cases were found to have YVDD with adenine741 changed into cytidine resulted in methionine552 changed into valine in which 6 cases with adenine669 changed into cytidine and leucine changed into methionine, 10 cases had YIDD motif mutation with guanosine743 altered thymidine methionine552 changed into isoleucine, including 3 cases with thymidine281 changed into cytidine and leucine565 altered proline.

CONCLUSIONThe gene chip can be used to test HBV YVDD,YIDD motif mutation compared with nucleotide sequences assay technique, the accuracy rate was 100%.