HBV Mutation Detail Information

Virus Mutation HBV Mutation A194T


Basic Characteristics of Mutations
Mutation Site A194T
Mutation Site Sentence Hepatitis B virus variant with the a194t substitution within reverse transcriptase before and under adefovir and tenofovir therapy.
Mutation Level Amino acid level
Mutation Type Nonsynonymous substitution
Gene/Protein/Region RT
Standardized Encoding Gene P  
Genotype/Subtype E
Viral Reference -
Functional Impact and Mechanisms
Disease Hepatitis B, Chronic     Liver Cirrhosis    
Immune -
Target Gene -
Clinical and Epidemiological Correlations
Clinical Information -
Treatment Abacavir(ADV);Tenofovir(TDF)
Location -
Literature Information
PMID 22342116
Title Hepatitis B virus variant with the a194t substitution within reverse transcriptase before and under adefovir and tenofovir therapy
Author Dupouey J,Gerolami R,Solas C,Colson P
Journal Clinics and research in hepatology and gastroenterology
Journal Info 2012 Apr;36(2):e26-8
Abstract Retrospective analysis of our local HBV reverse transcriptase (rt) sequence database including 973 sequences recovered from 616 patients identified one unique HBV DNA sequence harbouring amino acid (aa) substitution rtA194T, which has been suspected to confer reduced susceptibility to tenofovir but whose implication in antiviral resistance has not been confirmed. This sequence has been recovered from the blood sample of a 35-year-old man presenting with chronic hepatitis B and cirrhosis, at time of initiation of HBV therapy with adefovir (ADV). Retrospective analysis showed that viruses were rt194A eleven months earlier. Nonetheless, rt sequences recovered from the two sequential serum samples showed 98% nucleotide identity and were clustered in phylogenetic reconstruction. Clonal sequencing was performed retrospectively, which showed that rt194A HBV sequences were the only detected in the earliest sample and rt194T HBV sequences were the only detected in the later sample. HBV rtA194T mutants were still the majoritary quasi-species 17 months after being identified for the first time. HBV genotype determined by means of population sequencing then phylogeny reconstruction was E. HBV harboring a rt194T can be naturally observed, although very rarely, in absence of any prior therapy. Indeed, they represent six (0.2%) of three 110 sequences recovered from drug naive patients in the Stanford HBV sequence database (http://hivdb.stanford.edu/HBV/DB/cgi-bin/MutPrevByGenotypeRxHBV.cgi). In the present observation, we cannot interpret the virological response under anti-HBV therapy due to short follow-up and nonoptimal drug compliance, as indicated by patient's interview and TDF plasma Ctrough determination.
Sequence Data -
Mutation Information
Note
Basic Characteristics of Mutations
  • Mutation Site: The specific location in a gene or protein sequence where a change occurs.
  • Mutation Level: The level at which a mutation occurs, including the nucleotide or amino acid level.
  • Mutation Type: The nature of the mutation, such as missense mutation, nonsense mutation, synonymous mutation, etc.
  • Gene/Protein/Region: Refers to the specific region of the virus where the mutation occurs. Including viral genes, viral proteins, or a specific viral genome region. If the article does not specifically indicate the relationship between the mutation and its correspondence, the main
  • Gene/Protein/Region studied in the article is marked.
  • Genotype/Subtype: Refers to the viral genotype or subtype where the mutation occurs. If the article does not specifically indicate the relationship between the mutation and its correspondence, the main Genotype/Subtype studied in the article is marked.
  • Viral Reference: Refers to the standard virus strain used to compare and analyze viral sequences.
Functional Impact and Mechanisms
  • Disease: An abnormal physiological state with specific symptoms and signs caused by viral infection.
  • Immune: The article focuses on the study of mutations and immune.
  • Target Gene: Host genes that viral mutations may affect.
Clinical and Epidemiological Correlations
  • Clinical Information: The study is a clinical or epidemiological study and provides basic information about the population.
  • Treatment: The study mentioned a certain treatment method, such as drug resistance caused by mutations. If the study does not specifically indicate the relationship between mutations and their correspondence treatment, the main treatment studied in the article is marked.
  • Location: The source of the research data.
Literature Information
  • Sequence Data: The study provides the data accession number.