PRECORE/CORE VARIANTS OF HEPATITIS B VIRUS (HBV) IN THREE FAMILIES OF CHRONIC HBV CARRIERS WITH VARIABLE LIVER DISEASES

Abstract

It has been suggested that the different clinical course of liver disease in chronic hepatitis B virus (HBV) carriers is due to genomic variants of the HBV. In the present study we cloned the precore/core genes of the HBV isolated from three families of chronic HBV carriers who exhibited variable liver disease. A serial examination of the precore/core sequences from different time points revealed that variants of HBV were selected in both asymptomatic and diseased subjects. Precore mutations were seen to be persistent whereas certain core mutations were not cumulative. There appeared to be two mutation clustering regions in the core gene (codon 45-59 and codon 149-155). However, the clustering regions were seen in both asymptomatic and diseased subjects. Other mutations in the core were randomly distributed. There was no apparent link between the presence of mutations and the severity of liver disease. Possibility exists that region outside the precore/core might be responsible for the variability of liver disease.