# POSITION AA CATEGORY SCORE COMMENT 10 IVFRY PIMinor Yes L10I/V/F/R/Y are associated with resistance to most PIs when present with other mutations. L10I/V occur in 5-10% of untreated persons. L10F is a non-polymorphic mutation which is associated with decreased susceptibility to all PIs except ATV/r, SQV/r, and TPV/r. L10R/Y are rare poorly characterized mutations. 10 NOT IVFRY Other L10I/V/F/R/Y are PI-selected mutations. $listMutsIn{10(NOT IVFRY)} is a highly unusual mutation at this position. 11 IL PIMinor Yes V11IL are PI-selected mutation that are weakly associated with decreased FPV/r and DRV/r susceptibility. 11 NOT IL Other None 20 RMITV Other No K20R/M/I/T/V are PI-selected mutations. K20R is highly polymorphic and probably makes the least contribution to decreased PI susceptibility. K20I/M/T/V are nonpolymorphic in most subtypes. They appear to be selected most commonly by NFV and to reduce its susceptibility. 20 NOT RIMTV Other K20R/M/I/T/V are associated with resistance to multiple PIs when present with other mutations. $listMutsIn{20(NOT RIMTV)} is a highly unusual mutation at this position. 23 I PIMinor Yes L23I is a rare substrate cleft mutation that causes low-level NFV resistance. 23 NOT I Other L23I is a rare substrate cleft mutation that causes low-level NFV resistance. $listMutsIn{23(NOT I)} is a highly unusual mutation at this position. 24 I PIMinor Yes L24I is associated with reduced susceptibility to IDV/r and LPV/r and possibly SQV/r, and ATV/r when present with other mutations. It increases TPV/r susceptibility. 24 F Other Yes L24I is associated with reduced susceptibility to IDV/r and LPV/r and possibly SQV/r, and ATV/r when present with other mutations. It increases TPV/r susceptibility. L24F is a rare mutation at this position; its phenotypic effect is not known. 24 NOT FI Other L24I is associated with reduced susceptibility to IDV/r and LPV/r and possibly SQV/r, and ATV/r when present with other mutations. It increases TPV/r susceptibility. L24F is a rare mutation at this position; its phenotypic effect is not known. $listMutsIn{24(NOT FI)} is a highly unusual mutation at this position. 30 N PIMajor Yes D30N causes high-level resistance to NFV. 30 NOT N PIMinor D30N causes high-level resistance to NFV. $listMutsIn{D30(NOT N)} is a highly unusual mutation at this position. 32 I PIMajor Yes V32I is a substrate cleft mutation which is associated with reduced susceptibility to all PIs except SQV/r. 32 NOT I PIMinor V32I is a substrate cleft mutation which is associated with reduced susceptibility to all PIs except SQV/r. $listMutsIn{V32(NOT I)} is a highly unusual mutation at this position. 33 F PIMinor Yes L33F is selected by FPV/r, DRV/r, LPV/r, ATV/r, and TPV/r, and contribute resistance to these drugs. 33 I PIMinor Yes L33F is selected by FPV/r, DRV/r, LPV/r, ATV/r, and TPV/r, and contribute resistance to these drugs. L33I is less common than L33F but may have a similar effect. 33 V Other Yes L33V is a polymorphism that does not appear to be related to PI therapy or drug resistance. 33 NOT FIV Other None 35 G PIMinor Yes E35G is a nonpolymorphic mutation that is selected by NFV and which is weakly associated with decreased TPV susceptibility. 35 NOT G Other None 36 ILTV Other No M36I is weakly associated with PI resistance in subtype B viruses when present with other mutations. However, M36I is the consensus amino acid in most non-B subtypes. M36L/V/T are uncommon mutations at this position of unknown significance. 36 NOT ILTV Other None 43 T PIMinor Yes K43T is a nonpolymorphic PI-selected accessory mutation that in combination with other mutations is associated with reduced susceptibility to most PIs. It is also part of the genotypic susceptibility score (GSS) for TPV/r. 43 NOT T Other None 46 IL PIMajor Yes M46I/L decreases susceptibility to IDV/r, NFV, FPV/r, LPV/r, and ATV/r when present with other mutations. 46 V PIMinor Yes M46I/L decreases susceptibility to IDV/r, NFV, FPV/r, LPV/r, and ATV/r when present with other mutations. M46V is an uncommon PI-selected mutation at this position. 46 NOT ILV PIMinor M46I/L decreases susceptibility to IDV/r, NFV, FPV/r, LPV/r, and ATV/r when present with other mutations. M46V is an uncommon PI-selected mutation at this position. $listMutsIn{46(NOT ILV)} is a highly unusual mutation at this position. 47 V PIMajor Yes I47V decrease susceptibility to FPV/r, ATV/r, IDV/r, LPV/r, TPV/r, and DRV/r. 47 A PIMajor Yes I47A usually occurs with V32I and in this setting causes high-level LPV/r and FPV/r resistance and decreased DRV/r susceptibility. 47 NOT AV PIMinor I47V decrease susceptibility to FPV/r, ATV/r, IDV/r, LPV/r, TPV/r, and DRV/r. I47A usually occurs with V32I and in this setting causes high-level LPV/r and FPV/r resistance and decreased DRV/r susceptibility. $listMutsIn{47(NOT AV)} is a highly unusual mutation at this position. 48 V PIMajor Yes G48V causes high-level SQV/r resistance, intermediate ATV/r and NFV resistance, and low-level IDV/r and LPV/r resistance. 48 M PIMajor Yes G48V causes high-level SQV/r resistance, intermediate ATV/r and NFV resistance, and low-level IDV/r and LPV/r resistance. G48M is a less common mutation that appears to have similar effects on ARV susceptibility. 48 ASTQL PIMajor Yes G48V causes high-level SQV/r resistance, intermediate ATV/r and NFV resistance, and low-level IDV/r and LPV/r resistance.G48M is a less common mutation that appears to have similar effects on ARV susceptibility. G48A/S/T/Q are rare PI-selected mutations. 48 NOT VMALSTQ PIMinor G48V causes high-level SQV/r resistance, intermediate ATV/r and NFV resistance, and low-level IDV/r and LPV/r resistance. G48M is a less common mutation that appears to have similar effects on ARV susceptibility. G48A/S/T/Q/L are rare PI-selected mutations. $listMutsIn{48(NOT VMALSTQL)} is a highly unusual mutation at this position. 50 L PIMajor Yes I50L causes intermediate-to-high level resistance to ATV/r and increased susceptibility to the remaining PIs. 50 V PIMajor Yes I50V causes intermediate-to-high-level resistance to FPV/r, low-intermediate resistance to LPV/r and DRV/r, and increased susceptibility to TPV/r. 50 NOT LV PIMinor I50V causes intermediate-to-high-level resistance to FPV/r, low-intermediate resistance to LPV/r and DRV/r, and increased susceptibility to TPV/r. I50L causes intermediate-to-high level resistance to ATV/r and increased susceptibility to the remaining PIs. $listMutsIn{50(NOT LV)} is a highly unusual mutation at this position. 53 LY PIMinor Yes F53L is associated with decreased susceptibility to SQV/r and ATV/r. F53Y is a rare PI-selected variant at this position. 53 NOT LY Other F53L is associated with decreased susceptibility to SQV and ATV. F53Y is a rare PI-selected variant at this position. $listMutsIn{53(NOT LY)} is a highly unusual mutation at this position. 54 V PIMajor Yes I54V contributes resistance to each of the PIs except DRV/r. It is synergistic with V82A/S/T in decreasing PI susceptibility. 54 TAS PIMajor Yes I54T/A/S are PI-related mutations in combination with other mutations are associated with decreased susceptibility to each of the PIs. However, their effects have not been as well studied as I54V, I54M, or I54L. 54 L PIMajor Yes I54L occurs in patients receiving FPV/r, LPV/r, and DRV/r and reduces susceptibility to these PIs and to NFV and possibly ATV/r. It increases TPV/r susceptibility. 54 M PIMajor Yes I54M is selected by FPV/r, LPV/r, and DRV/r and reduces susceptibility to each of the PIs. 54 NOT ALMSTV PIMinor I54V/M/L/A/T/S have diverse effects on PI susceptibility. $listMutsIn{54(NOT ALMSTV)} is a highly unusual mutation at this position. 58 E PIMinor Yes Q58E is a nonpolymorphic PI-selected mutation associated with decreased susceptibility to TPV/r and possibly other PIs. 58 NOT E Other None 63 P Other No L63P is a common polymorphism that is also selected by PIs. 63 NOT P Other None 71 TVIL PIMinor Yes A71T/V are polymorphisms that occur in 2-3% of untreated persons but which increase in frequency in persons receiving PIs. A71I/L are nonpolymorphic mutations that occur in viruses with multiple PI-resistance mutations. 71 NOT TVIL Other None 73 STCA PIMinor Yes G73S/T/C/A are selected by and appear to be associated with decreased susceptibility to most, if not all, PIs. Their effect on SQV/r and NFV and possibly ATV/r appears to be greater than their effect on other PIs. 73 NOT STCA Other None 74 P PIMinor Yes T74P is a nonpolymorphic mutation that occurs more commonly in heavily treated patients. It has been associated with decreased virological response to TPV/r and to a lesser extent DRV/r. It is probably associated with decreased susceptibility to multiple PIs. 74 S Other Yes T74S is associated with reduced NFV susceptibility. It occurs in about 5% of untreated persons with subtype C viruses. 74 NOT PS Other None 76 V PIMajor Yes L76V reduces susceptibility to FPV/r, IDV/r, LPV/r, and DRV/r and increases susceptibility to SQV/r, ATV/r, and TPV/r. 76 NOT V PIMinor L76V reduces susceptibility to FPV/r, IDV/r, LPV/r, and DRV/r and increases susceptibility to SQV/r, ATV/r, and TPV/r. $listMutsIn{76(NOT V)} is a highly unusual mutation at this position. 77 I Other No V77I is a common polymorphism that is selected by NFV. 77 NOT I Other None 82 A PIMajor Yes V82A reduces susceptibility to IDV/r and LPV/r. With other mutations it is associated with reduced susceptibility to NFV, ATV/r, SQV/r, and FPV/r. 82 C PIMajor Yes V82C is a rare mutation that occurs primarily in protease genes containing multiple other PI-resistance mutations. 82 F PIMajor Yes V82F reduces susceptibility to IDV/r, LPV/r, FPV/r, DRV/r, and NFV. 82 I Other Yes V82I is a polymorphism that is common in some non-B subtypes; it has little if any effect on PI susceptibility. 82 L PIMajor Yes V82L is a rare TPV/r-selected mutation which decreases TPV/r susceptibility. Its effect on other PIs has not been characterized. 82 M PIMajor Yes V82M reduces IDV/r, LPV/r susceptibility in subtype G viruses. Its effect on other PIs has not been studied. 82 S PIMajor Yes V82S probably has a similar effect to V82T which reduces susceptibility to IDV/r, LPV/r, and TPV/r and with other mutations is associated with reduced susceptibility to NFV, ATV/r, FPV/r, and SQV/r. 82 T PIMajor Yes V82T reduces susceptibility to IDV/r, LPV/r, and TPV/r. With other mutations it is associated with reduced susceptibility to NFV and ATV/r. 82 NOT ATIFLMSC PIMinor V82A/T/F/L/M/S/C have diverse effects on multiple PIs. $listMutsIn{82(NOT ATIFLMSC)} is a highly unusual mutation at this position. 83 D PIMinor Yes N83D is a nonpolymorphic mutation that occurs more commonly in heavily treated patients. It is associated with a decreased virological response to TPV/r and probably contributes decreased susceptibility to other PIs. 83 NOT D Other N83D is a nonpolymorphic mutation that occurs more commonly in heavily treated patients. It is associated with a decreased virological response to TPV/r and probably contributes decreased susceptibility to other PIs. $listMutsIn{83(NOT D)} is a highly unusual mutation at this position. 84 V PIMajor Yes I84V causes intermediate/high-level resistance to ATV/r, FPV/r, IDV/r, NFV, and SQV/r; and low-level resistance to LPV/r, TPV/r, and DRV/r. 84 AC PIMajor Yes I84V causes intermediate/high-level resistance to ATV/r, FPV/r, IDV/r, NFV, and SQV/r; and low-level resistance to LPV/r, TPV/r, and DRV/r. I84A is an uncommon mutation that causes at least similar levels of resistance to each of the PIs. I84C is an even less common mutation that has not been well-characterized. 84 NOT ACV PIMinor I84V causes intermediate/high-level resistance to ATV/r, FPV/r, IDV/r, NFV, and SQV/r; and low-level resistance to LPV/r, TPV/r, and DRV/r. I84A is an uncommon mutation that causes at least similar levels of resistance to each of the PIs. I84C is an even less common mutation that has not been well-characterized. $listMutsIn{84(NOT ACV)} is a highly unusual mutation at this position. 85 V Other Yes I85V is a nonpolymorphic PI-selected mutation. 85 NOT V Other None 88 D PIMinor Yes N88D is selected by NFV. In combination with D30N, it synergistically reduces NFV susceptibility. 88 S PIMajor Yes N88S causes high-level resistance to NFV and ATV/r and low-level resistance to IDV/r; it increases susceptibility to FPV/r. 88 TG PIMajor Yes N88S causes high-level resistance to NFV and ATV/r and low-level resistance to IDV/r; it increases susceptibility to FPV/r. N88T/G are rare PI-selected mutations that have much less pronounced effects than N88S. 88 NOT DGST Other N88S causes high-level resistance to NFV and ATV/r and low-level resistance to IDV/r; it increases susceptibility to FPV/r. N88T/G are rare PI-selected mutations that have much less pronounced effects than N88S. $listMutsIn{88(NOT DGST)} is a highly unusual mutation at this position. 89 V PIMinor Yes L89V is a nonpolymorphic PI-selected accessory mutation which emerges commonly during treatment with DRV/r and in combination with other mutations is associated with decreased virological response to DRV/r salvage therapy. 89 IT Other No L89T/I are non-polymorphic PI-selected mutation of uncertain phenotypic and clinical significance. 89 M Other No L89M is a common polymorphism that is not associated with decreased PI susceptibility. 89 NOT VITM Other None 90 M PIMajor Yes L90M reduces susceptibility to NFV, SQV/r, ATV/r, and IDV/r. When present with other mutations it also reduces susceptibility to FPV/r and LPV/r. 90 NOT M PIMinor L90M reduces susceptibility to NFV, SQV/r, ATV/r, and IDV/r. When present with other mutations it also reduces susceptibility to FPV/r and LPV/r. $listMutsIn{90(NOT M)} is a highly unusual mutation at this position. 93 M Other No I93M is a rare PI-associated mutation; its effect on PI susceptibility is not known. 93 L Other No I93L is a common polymorphism. It is the consensus residue in most subtypes. In subtype B, it is weakly associated with PI treatment. 93 NOT LM Other None