HBV Mutation Detail Information

Virus Mutation HBV Mutation M204I


Basic Characteristics of Mutations
Mutation Site M204I
Mutation Site Sentence M204I/V and L180M are best recognised in association with 3TC resistance, but they may also be part of a combination of polymorphisms that underpins TDF resistance as there was no sustained viral suppression.
Mutation Level Amino acid level
Mutation Type Nonsynonymous substitution
Gene/Protein/Region RT
Standardized Encoding Gene P  
Genotype/Subtype D;A
Viral Reference -
Functional Impact and Mechanisms
Disease Hepatitis B, Chronic    
Immune -
Target Gene -
Clinical and Epidemiological Correlations
Clinical Information Y
Treatment Tenofovir(TDF)
Location South Africa
Literature Information
PMID 32663786
Title Evidence of tenofovir resistance in chronic hepatitis B virus (HBV) infection: An observational case series of South African adults
Author Mokaya J,Maponga TG,McNaughton AL,Van Schalkwyk M,Hugo S,Singer JB,Sreenu VB,Bonsall D,de Cesare M,Andersson M,Gabriel S,Taljaard J,Barnes E,Preiser W,Van Rensburg C,Matthews PC
Journal Journal of clinical virology : the official publication of the Pan American Society for Clinical Virology
Journal Info 2020 Aug;129:104548
Abstract INTRODUCTION: Tenofovir disoproxil fumarate (TDF) is widely recommended for treatment of chronic hepatitis B virus (HBV) infection because it is safe, affordable and has a high genetic barrier to resistance. TDF resistance associated mutations (RAMs) have been reported, but data are limited, particularly for Africa. We set out to identify potential RAMs in individuals with detectable HBV viraemia on TDF treatment. METHODS: We recruited adults with chronic HBV infection from Cape Town, South Africa, identifying individuals with a TDF resistance phenotype, defined as persistent HBV vireamia despite >12 months of TDF treatment. We sequenced HBV DNA using MiSeq Illumina with whole genome target enrichment, and sought potential TDF RAMs, based on a pre-defined list of polymorphisms. RESULTS: Among 66 individuals with chronic HBV (genotypes A and D), three met our clinical definition for TDF resistance, of whom two were coinfected with HIV. In one participant, the consensus HBV sequence contained nine polymorphisms that have been described in association with TDF resistance. Significant treatment non-adherence in this individual was unlikely, as HIV RNA was suppressed. TDF RAMs were also present in HBV sequences from the other two participants, but other factors including treatment non-adherence may also have had a role in failure of HBV DNA suppression in these cases. DISCUSSION: Our findings add to the evidence that RAMs in HBV reverse transcriptase may underpin a TDF resistant phenotype. This is the first time these RAMs have been reported from Africa in association with clinical evidence of TDF resistance.
Sequence Data MT210032;MT210033;MT210034
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.