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Basic Characteristics of Mutations
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Mutation Site
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T184I |
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Mutation Site Sentence
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By month 18, the rise in viral load was associated with the emergence of multiple mutations in the RT gene: 15% of HBV clones harbored the rtL180M+T184I+M204V mutations, 20% the rtL180M+A200V+M204V mutations, and interestingly 40% of the viral population harbored the rtL180M+A181V mutations without mutation at the rtM204 codon. |
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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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RT |
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Standardized Encoding Gene
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P
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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, Chronic
Liver Cirrhosis
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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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- |
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Treatment
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Lamivudine(LAM);Hepatitis B immunoglobulin(HBIG);Abacavir(ADV) |
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Location
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Haiti |
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Literature Information
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PMID
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17030194
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Title
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Selection of a multiple drug-resistant hepatitis B virus strain in a liver-transplanted patient
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Author
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Villet S,Pichoud C,Villeneuve JP,Trepo C,Zoulim F
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Journal
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Gastroenterology
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Journal Info
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2006 Oct;131(4):1253-61
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Abstract
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BACKGROUND & AIMS: Sequential anti-hepatitis B virus (HBV) therapy may lead to the selection of complex mutants. We analyzed the genetic and phenotypic evolution of the viral quasispecies of a patient who received successively lamivudine, add-on adefovir+lamivudine, followed by lamivudine+adefovir+hepatitis B immunoglobulins (HBIg) after orthotopic liver transplantation. METHODS: For genotypic analysis, a 1310-bp region of the polymerase gene was amplified, cloned, and sequenced. Huh-7 cells were transfected to compare the replication fitness of HBV mutants and their susceptibility to drugs. RESULTS: At baseline, all HBV genomes carried a wild-type (wt) RT gene but 22% harbored the sP120S and 55% the sC107stop mutations within the surface (S) gene associated with vaccine escape. Following viral breakthrough to lamivudine monotherapy, a complex mixture of lamivudine-resistant HBV strains prevailed. Interestingly, among these mutants emerged a population harboring only the rtL180M+A181V mutations, conferring lamivudine-resistance in vitro. After addition of adefovir to the ongoing treatment, viral load dropped, and the patient underwent an orthotopic liver transplantation and received HBIg. As viral load rose again, a single viral population was progressively selected, harboring the rtV173L+L180M+A181V+N236T and sP120S mutations. In vitro, this last mutant showed a level of replication reduced by only 30% compared to wt HBV and a strong resistance to both lamivudine (>1000-fold) and adefovir (>10-fold). It remained sensitive to tenofovir both in vitro and in vivo. CONCLUSIONS: We report the selection of a complex HBV mutant that escaped the antiviral pressure of lamivudine, adefovir, and HBIg, and provide insight on the process of selection via genotypic and phenotypic analysis.
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Sequence Data
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-
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