Related Experiment Video
Updated: Aug 24, 2026

Detection of Low Copy Number Integrated Viral DNA Formed by In Vitro Hepatitis B Infection
Published on: November 7, 2018
Hepatitis B virus genotypes and precore and core mutants in Brazilian patients
Roberta Sitnik1, João Renato Rebello Pinho, Dennis Armando Bertolini
1Serviço de Virologia, Instituto Adolfo Lutz, Av. Brigadeiro Luiz Antonio, 4701, 01401-002 São Paulo, SP, Brazil.
Abstract:
A method for genotyping hepatitis B virus by partial HBsAg gene sequencing with primers common to all known genotypes was developed. Mutations related to anti-HBs resistance are also detected with this method. Samples from 103 Brazilian patients were analyzed. Precore and core region of these viruses were also sequenced in 101 patients. Genotypes A, B, C, D, and F were found with frequencies of 49.5, 2.9, 13.6, 24.3, and 9.7%, respectively. Genotypes B and C were found only in Asian patients, whereas genotypes A, D, and F were more common in patients without an Asian background. Precore mutants were found in 32 (31.7%) of 101 patients, with a higher frequency in those infected with genotype D (22 of 25 [88.0%]). Analysis of nucleotide 1858 showed presence of thymine in all patients with genotypes B, C, and D and in a few patients with genotypes A (10.0%) and F (30.0%), who showed more frequently the presence of cytosine. This nucleotide was closely related to the presence of precore mutants. Mutations in the basal core promoter were found in 64 of 101 (63.4%) samples. These mutations were more frequent in patients infected with genotype F (90.0%) and less frequent in patients infected with genotype B (33.3%). Deletions in this region were found in two genotype C-infected patients.
Related Concept Videos
Viral Hepatitis I: Introduction
Hepatitis
Retroviruses
Viruses with RNA Genomes
Viral Mutations
Leishmaniasis

