title: Substitutions in the reverse transcriptase and protease genes of HIV-1 subtype B in untreated individuals and patients treated with antiretroviral drugs.
abstract: The nucleotide transition G-->A is known as a hypermutation due to its high prevalence in HIV-1 and other pathogens. However, the contribution of the G-->A transition in the generation of drug resistance mutations is unknown . Our objective was to ascertain the rate of nucleotide substitutions in protease (PR) and reverse transcriptase (RT) in both untreated and treated HIV-1 patients. Genotypic analysis was performed on viruses from both treated and untreated patients with subtype B infections. Nucleotide genomic diversity was compared with a consensus subtype B reference virus. Then, the prevalence of resistance-associated mutations in different subgroups of treated patients was evaluated in relation to the patterns of nucleotide transitions. In untreated patients (n = 50) G-->A was most prevalent, followed by A-->G, C-->T, and T-->C transitions. In treated patients (n = 51), the prevalence of A-->G was similar to that of G-->A. Among mutations that confer resistance to antiretroviral drugs, M184V was present in 76% of treated patients and K70R in 31% (A-->G transitions). Other frequent mutations in RT included T215Y (C-->A and A-->T substitutions), which was prevalent in 31% of treated patients. In PR, a L90M (T-->A substitution) was prevalent in 47% of protease inhibitor (PI)-treated patients. In conclusion, the G-->A transition was most prevalent in RT and PR among untreated patients. In contrast, A-->G was the most prevalent transition in patients treated with antiretroviral drugs.
authors.affiliation: McGill University, Montreal, Quebec, Canada.
authors.forename: Dan
authors.initials: D
authors.lastname: Turner
authors.forename: Bluma
authors.initials: B
authors.lastname: Brenner
authors.forename: Daniela
authors.initials: D
authors.lastname: Mosis
authors.forename: Chen
authors.initials: C
authors.lastname: Liang
authors.forename: Mark A
authors.initials: MA
authors.lastname: Wainberg
mesh_terms: D000225:Adenine; D044966:Anti-Retroviral Agents / Q000627:therapeutic use*; D001483:Base Sequence; D006147:Guanine; D015658:HIV Infections / Q000188:drug therapy* / Q000821:virology*; D016333:HIV Protease / Q000235:genetics*; D054303:HIV Reverse Transcriptase / Q000235:genetics*; D015497:HIV-1 / Q000145:classification / Q000235:genetics*; D006801:Humans
chemical_list: D044966:Anti-Retroviral Agents; D006147:Guanine; D054303:HIV Reverse Transcriptase; D016333:HIV Protease; D000225:Adenine