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Clinical significance of hepatitis B virus genotypes

Anna SF Lok, MD
Section Editor
Rafael Esteban, MD
Deputy Editor
Jennifer Mitty, MD, MPH


Hepatitis B virus (HBV), a member of the Hepadnaviridae family, replicates asymmetrically via reverse transcription of an RNA intermediate [1]. Because the viral polymerase lacks proofreading activity, mutations are common accounting for genetic heterogeneity of HBV. The estimated mutation rate of the hepadnavirus genome is about 2 x 10(4) base substitutions/site/year, about 100 times higher than that of other DNA viruses but about 100 to 1000 times lower than that of other RNA viruses [2]. According to phylogenetic analyses, HBV can be classified into 10 genotypes (A to J) based upon an inter-group divergence of 8 percent or more in the complete nucleotide sequence [3-5]. In the past few years, there is growing evidence suggesting that HBV genotypes influence clinical outcomes, HBeAg seroconversion rates, mutational patterns in the precore and core promoter regions, and response to antiviral therapy. This topic will provide a concise review on the clinical significance of HBV genotypes.


The prevalence of specific genotypes varies geographically [4,6-8]:

Genotype A is found mainly in Northern Europe, North America, India, and Africa

Genotype B and C are prevalent in Asia

Genotype D is more common in Southern Europe, the Middle East, and India


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Literature review current through: Sep 2016. | This topic last updated: Nov 25, 2014.
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