Human Immuno-Deficiency Virus Drug Resistance, Nuclesoide Reverse Transcriptase Inhibitors, Non-nuclesoide Reverse Transcriptase Inhibitors and associated drug resistance mutations in the Reverse Transcriptase Gene of Human Immuno Deficiency Virus-1

Resistance develops due to mutations in the reverse transcriptase gene of HIV-1 genome that does not respond towards the presence of effective drugs. Emergence of HIV-1 variants in the presence of effective drugs is a common occurrence. Drug resistance mutation means “the development of resistance mutations in the drug targeted HIV-1 genes” which causes the viruses to overcome the drug pressure. Thus resulting in failure to antiretroviral therapy. The detection of these mutations is possible by genotypic assay and the analysis of the effect of different drug concentrations towards the reverse transcriptase gene is possible by phenotypic assay. Genotyping of these mutations gives the information on therapeutic decision at the population and individual level. The frequency of mutation in the HIV-1 genes varies in the same population of a region or a city. The frequencies of mutations in the reverse transcriptase genes of HIV-1 lead to subtype diversity, drug resistance mutations and formation of recombinant isolates. The frequency of mutations in the reverse transcriptase gene is a cause of treatment failure by nucleoside/ nucleotide reverse transcriptase inhibitors and non-nucleoside reverse transcriptase inhibitors in a population level. The frequency of mutations in the reverse transcriptase gene is directly related to the prevalence of HIV-1 drug resistance mutations in a population or individual level. This review mainly focuses on the human immunodef ic iency v i rus drug resistance, nucleoside/nucleotide reverse transcriptase inhibitors, non-nucleoside reverse transcriptase inhibitors and associated drug resistance mutations in the reverse transcriptase gene of human immuno-deficiency virus-1. Abbreviations: HIV: Human Immunodeficiency Virus, AIDS:Aquired Immunodeficiency Syndrome. HIVDR: Human Immuno deficiency virus drug resistance, NRTIs:Nucleoside r e v e r s e t r a n s c r i p t a s e i n h i b i t o r s , NNRTIs:Non-nucleoside reverse transcriptase inhibitors, RT: Reverse transcriptase, PIs:Protease inhibitors, TAMs: Thymidine analogous mutations, NonTAMs: Non-thymidine analogous mutations.