Fig. 2.

Summary of nucleoside/nucleotide reverse transcriptase inhibitor drug-resistance mutations. Mutations are represented by their numeric position and amino acid letter code. The amino acid of the consensus wild-type sequence is represented by letters in the top row, while the amino acids of the mutations are below. Bold and underlining indicates mutations with high-level phenotypic and/or clinical resistance; bold indicates moderate phenotypic and/or clinical resistance; plain text indicates low-level resistance. Asterisks (***) represent increased susceptibility to the drug if the mutation is present. Refer to table I for a full list of drug name abbreviations and definitions. Adapted from the Stanford University HIV Drug Resistance Database.[40] Cons = consensus wild-type; Ins = insertion; MDR = multi-drug resistance.