Stanford University HIV Drug Resistance Database - A curated public database designed to represent, store, and analyze the divergent forms of data underlying HIV drug resistance.

PI Resistance Notes

Last updated on Feb 28, 2014
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10LFL10F is a common nonpolymorphic, PI-selected accessory mutation associated with reduced susceptibility to each of the PIs except ATV, SQV, and TPV.
10LIVL10I/V are polymorphic, PI-selected accessory mutations that reduce PI susceptibility or increase the replication of viruses with other PI-resistance mutations.
10LRYL10R/Y are rare, nonpolymorphic PI-selected accessory mutations. Their effects on PI susceptibility have not been well studied.
11VILV11I is a minimally polymorphic PI-resistance accessory mutation that is often selected in patients receiving DRV. It is associated with minimal reductions in DRV and FPV susceptibility. It is included in the Tibotec GSS for DRV. V11L is a nonpolymorphic accessory PI-resistance mutation that is also associated with minimal reductions in DRV and FPV susceptibility.
20KIK20I is the consensus amino acid in subtype G and CRF02_AG. In subtypes B and C, K20I is a PI-selected mutation that appears to reduce NFV susceptibility.
20KMVK20M/V are rare, relatively nonpolymorphic PI-selected mutations that have not been well studied.
20KRK20R is a highly polymorphic, PI-selected accessory mutation that improves HIV-1 replication fitness in viruses with other PI-resistance mutations.
20KTK20T is a nonpolymorphic accessory PI-selected mutation that is associated with reduced susceptibility to each of the PIs except SQV and TPV.
23LIL23I is an uncommon nonpolymorphic mutation selected primarily by NFV. It causes low/intermediate-level resistance to NFV.
24LFML24F is an uncommon nonpolymorphic PI-selected mutation that appears to have a susceptibility profile similar to L24I. L24M is a rare nonpolymorphic PI-selected mutation that has not been well studied.
24LIL24I is a nonpolymorphic mutation selected by IDV and, less often, LPV. It reduces susceptibility to FPV, IDV, LPV, SQV, ATV and NFV. It increases susceptibility to TPV.
30DND30N is a nonpolymorphic substrate-cleft mutation that causes high-level resistance to NFV.
32VIV32I is a nonpolymorphic substrate-cleft mutation associated with reduced susceptibility to each PI except SQV. It is included in the Tibotec DRV GSS.
33LFL33F is a relatively nonpolymorphic accessory mutation selected by DRV, FPV, LPV, NFV and TPV. In combination with other PI-resistance mutations, L33F is associated with reduced susceptibility to these PIs. It is included in the Tibotec DRV GSS.
33LIL33I is a relatively nonpolymorphic PI-selected mutation that appears to have minimal, if any, effects on PI susceptibility.
33LVL33V is a polymorphism that does not appear to be selected by PIs or to be associated with reduced PI susceptibility.
35EGE35G is a relatively nonpolymorphic PI-selected mutation that is weakly associated with reduced NFV and TPV susceptibility.
43KTK43T is a nonpolymorphic PI-selected accessory mutation that, in combination with other PI-resistance mutations, is associated with reduced susceptibility to most PIs. It is also part of the GSS for TPV.
46MILM46I/L are nonpolymorphic PI-selected mutations that reduce susceptibility to IDV, NFV, FPV, LPV and ATV when present with other mutations. M46L also reduces susceptibility to TPV.
46MVM46I/L are nonpolymorphic PI-selected mutations that reduce susceptibility to IDV, NFV, FPV, LPV and ATV when present with other mutations. M46L also reduces susceptibility to TPV. M46V is a rare nonpolymorphic PI-selected mutation that has not been well studied.
47IAI47A is a nonpolymorphic mutation selected by LPV. It usually occurs in combination with V32I and it confers high-level resistance to LPV and FPV and low/intermediate-resistance to the remaining PIs except ATV and SQV. It increases susceptibility to SQV.
47IVI47V is a nonpolymorphic mutation selected by IDV, FPV, LPV and DRV. It is associated with reduced susceptibility to each of the PIs except SQV and ATV. I47V is included in the Tibotec DRV GSS.
48GASTQLG48V causes high-level resistance to SQV, intermediate-level resistance to ATV and NFV, and low-level resistance to IDV and LPV. G48M is a less common mutation that appears to have similar effects on PI susceptibility. G48A/S/T/Q are rare nonpolymorphic PI-selected mutations that occur in patients who have received multiple PIs.
48GMG48V is a nonpolymorphic substrate-cleft mutation selected by SQV and, less often, by IDV and LPV. It confers high-level resistance to SQV, intermediate-level resistance to ATV, and low-level resistance to NFV, IDV and LPV. G48M is a 2-base pair nonpolymorphic mutation selected in patients who have received multiple PIs. It causes high-level resistance to SQV, intermediate-level resistance to ATV and NFV and low-level resistance to IDV and LPV.
48GVG48V is a nonpolymorphic substrate-cleft mutation selected by SQV and, less often, by IDV and LPV. It confers high-level resistance to SQV, intermediate-level resistance to ATV, and low-level resistance to NFV, IDV and LPV.
50ILI50L is a nonpolymorphic substrate-cleft mutation selected by ATV. It causes intermediate/high-level resistance to ATV and increases susceptibility to the remaining PIs.
50IVI50V is a nonpolymorphic substrate-cleft mutation selected by FPV, LPV and DRV. It reduces susceptibility to these PIs and increases susceptibility to TPVI50V is included in the Tibotec DRV GSS.
53FLYF53L is a nonpolymorphic mutation selected primarily by SQV, IDV, ATV, and LPV. It reduces susceptibility primarily to ATV, SQV, and NFV. F53Y is a rare nonpolymorphic PI-selected mutation that has not been well studied.
54ILI54L is a nonpolymorphic mutation selected by FPV, LPV and DRV. It reduces susceptibility to these PIs and possibly to ATV, IDV, NFV and SQV. It increases susceptibility to TPV. It is in the Tibotec DRV GSS.
54IMI54M is a nonpolymorphic mutation selected by FPV, LPV and DRV. It reduces susceptibility to each of the PIs. It is in the Tibotec DRV GSS.
54ITASI54A/T/S are nonpolymorphic PI-selected mutations that occur almost exclusively in patients who have received multiple PIs. I54A/T/S are associated with reduced susceptibility to each of the PIs except DRV.
54IVI54V is a nonpolymorphic mutation selected primarily by IDV and LPV. It reduces susceptibility to each of the PIs except DRV. It synergistically reduces PI susceptibility when present in combination with V82 mutations.
58QEQ58E is a nonpolymorphic accessory PI-selected mutation associated with reduced susceptibility to TPV and possibly other PIs.
71ATVILA71T/V are polymorphisms that occur in 2-3% of untreated persons. They increase in prevalence in persons receiving PIs. A71I/L are nonpolymorphic mutations that occur in viruses with multiple PI-resistance mutations.
73GSTCAG73S/T/C/A are nonpolymorphic mutations that are selected primarily by ATV, IDV, NFV and SQV. They are associated with reduced susceptibility to these PIs and possibly to DRV, FPV and LPV.
73GVG73V is a nonpolymorphic PI-selected mutation that has not been well studied.
74TPT74P is a nonpolymorphic PI-selected accessory mutation that occurs primarily in viruses from patients who have received multiple PIs. It is associated with reduced susceptibility to each of the PIs. It is included in the Boehringer-Ingelheim TPV and Tibotec DRV GSS.
74TST74S is a polymorphic mutation weakly selected by most PIs and associated with low-level resistance to NFV.
76LVL76V is a nonpolymorphic mutation selected by IDV, LPV and DRV. It reduces susceptibility to these PIs and to FPV. It increases susceptibility to ATV, SQV and TPV. L76V is included in the Tibotec DRV GSS.
82VAV82A is a nonpolymorphic substrate-cleft mutation selected primarily by IDV and LPV. It reduces susceptibility to these PIs and causes cross-resistance to ATV and NFV. When it occurs in combination with additional PI-resistance mutations it is also associated with reduced susceptibility to SQV and FPV.
82VCV82C is an uncommon nonpolymorphic 2-base-pair substrate-cleft mutation that develops in viruses with multiple PI-resistance mutations from patients who received multiple PIs. Its effects on PI susceptibility have not been well studied.
82VFV82F is a nonpolymorphic substrate-cleft mutation selected primarily in patients who have received multiple PIs. It causes reduced susceptibility to DRV, FPV, IDV, LPV and NFV.
82VIV82I is a highly polymorphic substrate-cleft mutation that is not selected by PIs. It is the consensus amino acid in subtype G viruses.
82VLV82L is an uncommon nonpolymorphic substrate-cleft mutation selected by TPV. It reduces TPV susceptibility but its effects on other PIs have not been well studied.
82VMIn most subtypes, V82M is a 2-base-pair substrate-cleft mutation that develops in viruses with multiple PI-resistance mutations from patients who received multiple PIs. In subtype G, V82M is a 1-base-pair mutation. V82M reduces susceptibility to IDV, LPV and possibly other PIs.
82VTSV82T is a nonpolymorphic substrate-cleft mutation selected in patients who received IDV, TPV, or multiple PIs. It reduces susceptibility to these PIs and to ATV, LPV, and NFV. V82T is included in the Boehringer-Ingelheim TPV GSS. V82S is a nonpolymorphic mutation that appears to have a resistance profile similar to V82T.
83NDN83D is a nonpolymorphic mutation selected primarily in patients who have received multiple PIs. It is associated with reduced susceptibility to ATV, IDV, NFV, SQV and TPV. It is included in the Boehringer-Ingelheim GSS for TPV.
84IACI84A is a rare nonpolymorphic PI-selected substrate-cleft mutation associated with high-level resistance to each of the PIs. I84C is a rare nonpolymorphic PI-selected mutation associated with varying degrees of reduced susceptibility to each of the PIs.
84IVI84V is a nonpolymorphic substrate-cleft mutation selected by each of the PIs. It causes high-level resistance to ATV, FPV, IDV, NFV and SQV, intermediate-level resistance to LPV and TPV, and low-level resistance to DRV.
85IVI85V is a nonpolymorphic PI-selected mutation. It has minimal, if any, effects on PI susceptibility.
88NDN88D is selected by NFV. In combination with D30N, it synergistically reduces susceptibility to NFV. It may also be associated with reduced susceptibility to ATV and SQV.
88NSN88S is a nonpolymorphic mutation selected by NFV and ATV. It causes high-level resistance to NFV and ATV and low-level resistance to IDV and SQV. It increases susceptibility to FPV.
88NTGN88G/T are extremely rare nonpolymorphic PI-selected mutations that reduce susceptibility to NFV and ATV.
89LITL89T/I are nonpolymorphic PI-selected mutation of uncertain phenotypic and clinical significance.
89LML89M is a common polymorphism that is not associated with reduced PI susceptibility. It is the consensus amino acid in most non-B subtypes.
89LVL89V is a nonpolymorphic accessory mutation selected by IDV, NFV, FPV, LPV and DRV. It reduces susceptibility to these PIs. L89V is included in the Tibotec DRV GSS (de Meyer 2008).
90LML90M is a nonpolymorphic mutation selected primarily by SQV, NFV, IDV and LPV. It reduces susceptibility to each of the PIs except TPV and DRV.