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Basic Characteristics of Mutations
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Mutation Site
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L180M |
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Mutation Site Sentence
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This patient also carried the L180M mutation. |
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Mutation Level
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Amino acid level |
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Mutation Type
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Nonsynonymous substitution |
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Gene/Protein/Region
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Standardized Encoding Gene
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Genotype/Subtype
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- |
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Viral Reference
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-
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Functional Impact and Mechanisms
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Disease
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Hepatitis B Virus Infection
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Immune
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- |
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Target Gene
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-
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Clinical and Epidemiological Correlations
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Clinical Information
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Y |
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Treatment
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- |
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Location
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South Africa |
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Literature Information
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PMID
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19382250
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Title
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Frequent detection of hepatitis B virus variants associated with lamivudine resistance in treated South African patients infected chronically with different HBV genotypes
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Author
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Selabe SG,Song E,Burnett RJ,Mphahlele MJ
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Journal
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Journal of medical virology
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Journal Info
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2009 Jun;81(6):996-1001
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Abstract
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This retrospective study investigated and characterized the YMDD motif of the hepatitis B virus (HBV) reverse transcriptase (RT) gene, in sequential samples of 17 South African patients with chronic hepatitis B infection on lamivudine treatment. The profile of HBV genotypes as well as the genetic variability of pre-core (pre-C) and basal core promoter regions (BCP) were also determined in these patients. Mutations within the RT gene were determined by direct sequencing using SpectruMedix SCE 2410 genetic analyzer and INNO-LiPA HBV DR (Innogenetics), while the genetic variability of the pre-C/BCP and surface gene were determined by direct sequencing only. HBV genotypes were determined by analysis of the surface, core and RT genes using a web-based genotyping tool (NCBI). HBV DNA was quantified using Cobas Amplicor HBV Monitor assay (Roche Diagnostics). Of the 17 patients, 13 (76.5%) carried YMDD mutations: 7 with rtM204I (2 HBeAg-positive and 5 HBeAg-negative) and 6 with rtM204V (4 HBeAg-positive and 2 HBeAg-negative). Of the 13 patients with resistant HBV strains, 8 (61.5%) carried genotype A, 3 (23%) genotype B, and 2 (15.3%) genotype C. Overall, only 5 of 13 (38%) patients with YMDD mutations experienced genotypic viral drug resistance and treatment failure. Of the 17 patients, 3 carried both pre-C (G1896A) and BCP (A1762T/G1764A) mutants, 1 pre-C only and 1 BCP only. This study demonstrated frequent detection of mutations associated with lamivudine-resistance in therapy-experienced South African patients infected chronically with different HBV genotypes, and confirmed that these mutations are not always accompanied by clinical relapse.
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Sequence Data
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-
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