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Basic Characteristics of Mutations
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Mutation Site
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Y472D |
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Mutation Site Sentence
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Of amino acid 432 to 574 of the polymerase protein, two substitutions, Y472D and A529T, were found between S1 and S2 sera, and three substitutions, Y472D, L528M, and M552I, were found between S1 and S3 sera. |
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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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P |
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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
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Lamivudine(LAM) |
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Location
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- |
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Literature Information
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PMID
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10827158
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Title
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Clearance of the original hepatitis B virus YMDD-motif mutants with emergence of distinct lamivudine-resistant mutants during prolonged lamivudine therapy
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Author
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Yeh CT,Chien RN,Chu CM,Liaw YF
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Journal
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Hepatology (Baltimore, Md.)
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Journal Info
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2000 Jun;31(6):1318-26
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Abstract
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Tyrosine-methionine-aspartate-aspartate (YMDD)-motif mutants may emerge and elicit immune clearance during prolonged lamivudine treatment. The aim of this study was to investigate the virological events following development of the original mutants. Twenty-three patients who developed YMDD-motif mutants during the Asian lamivudine trial were included. Serial serum samples from these patients were subjected to sequence analysis to identify new mutants. Site-directed mutagenesis experiments were performed to investigate whether the new mutations were responsible for lamivudine resistance. Of the 23 patients included, 13 harbored either one or a mixture of the two common YMDD-motif mutants (methionine 552-to-isoleucine [M552I] and leucine 528-to-methionine/methionine 552-to-valine [L528M/M552V]) throughout the course, whereas in the remaining 10 patients, distinct mutants became dominant over the original mutants to cause continuing chronic hepatitis. Of them, 3 developed an alanine 529-to-threonine (A529T) mutant, 6 developed a leucine 528-to-methionine/methionine 552-to-isoleucine (L528M/M552I) mutant, and 1 developed these two mutants sequentially. Site-directed mutagenesis experiments confirmed that the aforementioned mutations were responsible for the resistance to lamivudine in vitro. The nucleotide substitution in the A529T mutant concomitantly generated a stop codon at the surface gene, leading to impaired secretion of HBsAg. Strikingly, the replication of this mutant was lamivudine dependent. These results suggested that distinct lamivudine-resistant mutants could emerge and replace the original YMDD-motif mutants as the cause of continuing chronic hepatitis during prolonged lamivudine therapy.
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Sequence Data
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-
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