ABSTRACT
Introduction: More than 350 million people are chronic carriers of HBV and many of them develop progressive diseases, including cirrhosis and hepatocellular carcinoma. Many of those infected develop persistent disease and a proportion goes on to develop liver failure and cancer. Researchers showed that double mutations of the x gene at position 1762 and 1764, have been found in chronic hepatitis B. These mutations were proposed to be associated with fulminant hepatitis B increasing risk of hepatocellular carcinoma. This project aimed to investigate mutation in the x gene region of HBV infected patients in Golestan province, Iran. Method: 100 patients were entered in this study. Hepatitis B viral DNA was extracted from plasma and PCR was performed using specific primers. Direct sequencing and alignment of x gene were applied using reference sequence from Gene Bank database (Okamoto, 1988; Accession number AB033559). Results: Among the chronic HBV patients 51% were male. The results showed that 49% of patients had A1762T, G1764A mutations changing AGG to stop codon TGA. 27% and 24% of cases were showed mutation only in A1762T and G1764A positions respectively. Conclusion: This study was shown presence of X gene mutation in HBV infected people in Golestan province, Iran. The rate of mutation in two positions 1762 and 1764 of HBV genotype D X gene was higher than the average rate of the world (34%).