Method: ETV resistance: Two or more amino acid substitutions are required across the HBV RT protein to confer resistance to ETV which could occur as a combination of M204I/V with one or more of the following substitutions L80I/V, I163V, I169T, V173L, L180M, A181S/T/V, T184X, A186T, S202C/G/I/R, M250I/V and/or C256S/G.
Characterization and Clinical Significance of Natural Variability in Hepatitis B Virus Reverse Transcriptase in Treatment-Naive Chinese Patients by Sanger Sequencing and Next-Generation Sequencing.
PMID: 31189581
2019
Journal of clinical microbiology
Discussion: In this study, except rtA181T, the classical primary drug resistance mutations (i.e., I169T, A181T/V, T184
Discussion: In this study, using next-generation sequencing, mutations were found at rt202 (rtS202R/I/N/C/G), rt204 (rtM204L/R/I), rt236 (rtN236T/K/H), and rt250 (rtM250I/L) (Table 5).
[Determination of reverse transcriptase inhibitor nucleoside analogue resistance profile in pretreatment phase of patients with viral hepatitis B].
Abstract: Primary drug resistance mutations such as rtI169T, rtA181T/V, rtT184A/C/F/G/I/L/M/S, rtA194T, rtS202C/G/I, rtM204I/V/S, rtN236T, rt M250I/L/V and rtV173L were not detected in any of the patient samples.
Naturally occurring hepatitis B virus reverse transcriptase mutations related to potential antiviral drug resistance and liver disease progression.
PMID: 29713126
2018
World journal of gastroenterology
Method: Our literature based pooled incidence data showed that of primary drug resistance mutations, M204I/V is the most frequently encountered in treatment-naive patients (5.89%), which was far more than the pooled mutation rate of rtA181T/V, rtS202C/G/I and rtN236T (incidence: 1.16%, 0.85% and 0.81%, respectively).
Table: S202C/G
HBV Drug Resistance Substitutions Existed before the Clinical Approval of Nucleos(t)ide Analogues: A Bioinformatic Analysis by GenBank Data Mining.
Introduction: Resistance to ETV needs a combination of substitutions of rtM204I/V and rtL180M plus one of the following substitutions: rtI169T, rtT184A/C/F/G/I/L/M/S, rtS202C/G/I or rtM250I/L/V.
Discussion: This suggests that these atypical substitutions might not play important roles in the emergence of NUCr as compared to rtA181T/V, rtS202C/G/I
Clinical features and viral quasispecies characteristics associated with infection by the hepatitis B virus G145R immune escape mutant.
Result: We also screened several mutations relevant to antiviral resistance, such as I169L, L180M, A181V, T184I, S202C, M204V/I, N236T and M250I in the RT region.
Comparison of Detection Rate and Mutational Pattern of Drug-Resistant Mutations Between a Large Cohort of Genotype B and Genotype C Hepatitis B Virus-Infected Patients in North China.
PMID: 27792585
2017
Microbial drug resistance (Larchmont, N.Y.)
Abstract: For entecavir-resistant mutations, HBV/C-infected patients had a higher detection rate of rtM204 V/I+T184 substitution or S202G/C (3.66% vs.
Epidemiology study of HBV genotypes and antiviral drug resistance in multi-ethnic regions from Western China.
Result: It is worth noting that we did not observe any of the common NA-related resistance mutations including rtM204V/I, rtS202C/G/I, rtL180M, rtA181T/V, rtT184A/I/L/G/C/M, rtA194T, rtI169T, rtV173L, rtL80I, rtN236T, and
ViMRT
HBV mutation literature information.
PMID: 
2022
Frontiers in microbiology
