Detection of Drug Resistance Mutation in the YMDD Region of Polymerase Gene of HBV in Hepatitis B Patients by Ligase Chain Reaction (LCR)

Aim and background. Hepatitis B and its incidence are considered as an endemic disease worldwide. In addition to creation of critical and chronic hepatitis B disease, in patients who suffer from chronic kind of this infection there are hepatocelullar carcinoma or hepatic cirrhosis presumptions or other kinds of defections. HBV (hepatitis B virus) is also up to 98 percent sensitive to some medicines like lamivudine. Lamivudine blocks viral DNA polymerase enzyme reverse transcriptase action through binding to its specific regions. But problem may be formed in patients whom are exposed to lamivudine for long time; a new mutation occurs in C domain of YMDD motif and of viral DNA polymerase gene that leads to lamivudine resistance. Molecular diagnosis of this mutation is essential with regard to considerable relationship between mutation occurrence rate and infection incidence range due to host immune system. We chose LCR method due to its ease achievability compared with others to detect the mutation. Materials and methods. 62 Nested PCR viral polymerase gene samples of HBV using LCR were surveyed. Five pairs of 21_26bps oligonucleotides were designed for both wild type and mutant YMDD region which amplify a 47bps region.Results. 51 of 62 patients have been non mutant in YMDD motif (82.25%) while 11 patients have been mutant in YMDD motif (17.74%). LCR. Conclusion. Investigation of LCR conclusions has shown that there is both wild and mutant type of HBV in patients. For this reason, we utilized mutant oligonucleotides and its bonds on gel were seen. Results are completely in conformation to sequencing conclusions.