Risk factors for selection of the L74I reverse transcriptase mutation in human immunodeficiency virus type 1-infected patients.

We analyzed 3,475 human immunodeficiency virus sequences and 241 therapeutic histories. The L74I mutation was carried by 7% of viruses. L74I was strongly associated with T215F, K70R, and V75M/S/T/A mutations and increased with the number of thymidine analog mutations.