Open AccessGenotypes and viral variants in chronic hepatitis B: A review of epidemiology and clinical relevance
Author(s) -
Catherine Croagh,
Paul Desmond,
Sally Bell
Publication year - 2015
Publication title -
world journal of hepatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.913
H-Index - 55
ISSN - 1948-5182
DOI - 10.4254/wjh.v7.i3.289
Subject(s) - medicine , genotype , hepatocellular carcinoma , hepatitis b virus , hbeag , liver disease , liver cancer , virology , hepatitis b , viral hepatitis , immunology , disease , virus , gene , biology , genetics , hbsag
The Hepatitis B Virus (HBV) has a worldwide distribution and is endemic in many populations. It is constantly evolving and 10 genotypic strains have been identified with varying prevalences in different geographic regions. Numerous stable mutations in the core gene and in the surface gene of the HBV have also been identified in untreated HBV populations. The genotypes and viral variants have been associated with certain clinical features of HBV related liver disease and Hepatocellular carcinoma. For example Genotype C is associated with later hepatitis B e antigen (HBeAg) seroconversion, and more advanced liver disease. Genotype A is associated with a greater risk of progression to chronicity in adult acquired HBV infections. Genotype D is particularly associated with the precore mutation and HBeAg negative chronic hepatitis B (CHB). The genotypes prevalent in parts of West Africa, Central and South America, E, F and H respectively, are less well studied. Viral variants especially the Basal Core Promotor mutation is associated with increased risk of fibrosis and cancer of the liver. Although not currently part of routine clinical care, evaluation of genotype and viral variants may provide useful adjunctive information in predicting risk about liver related morbidity in patients with CHB.