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Basic Characteristics of Mutations
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Mutation Site
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M204V |
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Mutation Site Sentence
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In conclusion, this study showed that virological and biochemical breakthrough due to ETV could occur in patients infected with LAM-resistant HBV and confirmed that the addition of rtS202G substitution to the rtL180M + M204V mutant strain is responsible for ETV resistance and we could treat the resistant mutant successfully. |
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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 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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- |
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Treatment
|
Lamivudine(LAM);Entecavir(ETV) |
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Location
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- |
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Literature Information
|
|
PMID
|
17935165
|
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Title
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Successful treatment of an entecavir-resistant hepatitis B virus variant
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Author
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Yatsuji H,Hiraga N,Mori N,Hatakeyama T,Tsuge M,Imamura M,Takahashi S,Fujimoto Y,Ochi H,Abe H,Maekawa T,Suzuki F,Kumada H,Chayama K
|
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Journal
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Journal of medical virology
|
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Journal Info
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2007 Dec;79(12):1811-7
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Abstract
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Emergence of a lamivudine (LAM)-resistant hepatitis B virus (HBV) with amino acid substitutions in the YMDD motif is a well-documented problem during long-term LAM therapy. Entecavir (ETV) is a new drug approved for treatment of HBV infection with or without LAM-resistant mutants. This report describes an ETV-resistant strain of HBV, which emerged after prolonged ETV therapy in a patient who did not respond to LAM therapy. Direct sequence analysis of the ETV-resistant strain showed appearance of amino acid substitution rtS202G in the reverse transcriptase (RT) domain, together with rtL180M + M204V substitution that had developed at the emergence of LAM-resistant mutant. In vitro analysis demonstrated that the rtL180M + M204V + S202G mutant strain displayed a 200-fold and a 5-fold reduction in susceptibility to ETV compared with the wild- type and the rtL180M + M204V mutant strain, respectively. Adefovir was effective against the ETV-resistant strain both in vitro and during the clinical course. In conclusion, this study showed that virological and biochemical breakthrough due to ETV could occur in patients infected with LAM-resistant HBV and confirmed that the addition of rtS202G substitution to the rtL180M + M204V mutant strain is responsible for ETV resistance and we could treat the resistant mutant successfully.
|
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Sequence Data
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-
|