Related Experiment Video
Updated: Jun 5, 2026

An Affordable HIV-1 Drug Resistance Monitoring Method for Resource Limited Settings
Published on: March 30, 2014
Impact of HIV-1 group O genetic diversity on genotypic resistance interpretation by algorithms designed for HIV-1
Agnès Depatureaux1, Charlotte Charpentier, Marie Leoz
1Laboratoire associé au Centre National de Référence du VIH, CHU de Rouen, Rouen, France. jean-christophe.plantier@univ-rouen.fr
Background:
HIV-1 group O (HIV-O) is characterized by a high genetic divergence from HIV-1 group M viruses. Little is known about the therapeutic impact of this diversity. The aim of this study was to assess in a large series of samples (1) the genotypic impact of natural polymorphism of the HIV-O reverse transcriptase and protease genes; and (2) the predictive value of resistance interpretation algorithms developed for HIV-1 group M when used for highly mutated HIV-O viruses.
Methods:
Sixty-eight antiretroviral-naive and 9 highly antiretroviral-experienced HIV-O-infected patients were included. The viruses were sequenced and resistance-associated mutations were identified using 3 different algorithms (Agence Nationale de Recherches sur le SIDA et les hépatites virales, Rega, Stanford).
Results:
All HIV-O samples naturally exhibited the A98G and V179E resistance mutations in the reverse transcriptase region; 54% of samples presented the Y181C mutation, conferring resistance to nonnucleoside reverse transcriptase inhibitors. Twelve minor resistance mutations, present in more than 75% of the protease sequences, led to the different algorithms giving discrepant results for nelfinavir and saquinavir susceptibility. A marked virological response was observed in 8 of the 9 antiretroviral-experienced patients, despite the prediction of limited activity of the combination for 5 to 8 patients according to the algorithm used.
Conclusions:
The high level of natural polymorphism in HIV-O genes, and the important discrepancies between genotypic resistance interpretation and the virological response, emphasize the need for resistance algorithm rules better adapted to HIV-O.
Related Concept Videos
Principles of Pharmacogenetics: Types of Genetic Variants
Retrovirus Life Cycles
Viral Mutations
Pharmacogenetic Phenotypes: Alterations in Pharmacokinetics, Drug Targets and Biologic Milieu
Genetic Variation
Genes exist in different versions called alleles, which...
Mutation, Gene Flow, and Genetic Drift

