Greg+, a molecular biology mutation interpretation tool

Greg+ is a molecular biology tool for mutation detection, analysis and interpretation.

Greg+ has been developed at the Grenoble University Hospital in France in association with virologists and clinicians specialized in infectiology. It assists biologists and clinicians adapting patient treatment based on resistance algorithms validated by the ANRS virologist groups. Algorithms are regularly updated and integrated into this solution to keep interpretation in synchronization with the latest research results. A database linking biological and demographic data is associated with sequences for each patient sample and allows longitudinal follow-ups. Moreover, it has been designed with collaborative studies in mind considering that all local databases can be shared between Greg+ users.

It supports:

  • HIV with associated sequences and resistance tables in the database for reverse transcriptase, protease, integrase, GP41 and CCR5/CXCR4 typing using the algorithm described by Delobel et al, J Clin Microbiol 2007;45:5 1572-80
  • HBV reverse transcriptase
  • HCV protease
  • Sequence submission to web analysis services directly from Greg+: Stanford (HIVdb Program), Geno2pheno (HIV: resistance, coreceptor and integrase; HCV and HBV)

For each microorganism/gene sequence, a BLAST (basic local alignment search tool) analysis can be performed as well to produce the viral genotype (for this purpose HCV 5'UTR and NS5B genes were also included). After mutation analysis and interpretation, a report is generated with the conclusion on the resistance degree for each drug.

This software is downloadable from this Grenoble University Hospital website (with a password) and runs locally and offline.

If you are interested in our mutation interpretation tool and would like to test it, feel free to contact us at:



Financial support is granted by the ANRS (French National Agency for Research on AIDS and Viral Hepatitis, an autonomous agency at Inserm).

ANRS website (in french) Inserm website Grenoble University Hospital website (in french)