| Position | Cons | AA | Comment |
| 90 | V | I | V90I is a common polymorphism that was weakly associated with decreased ETR response in the DUET studies. However, it has minimal if any effect on NNRTI susceptibility. |
| 98 | A | G | A98G reduces NVP susceptibility by 2 to 3-fold. It is selected by NRTIs and NNRTIs. It was associated with a decreased ETR response in the DUET studies but it has little if any effect on ETR susceptibility. |
| 98 | A | S | A98S is a common polymorphism that does not reduce NNRTI susceptibility. |
| 100 | L | I | L100I usually occurs in combination with K103N. By itself it causes intermediate resistance to NVP, DLV, and EFV, and 2 to 4-fold decreased ETR susceptibility. In combination with K103N it causes high-level resistance to NVP, DLV, and EFV and 10 to 20-fold decreased ETR susceptibility. L100I increases susceptibility to AZT and TDF. |
| 100 | L | NOT I | L100I usually occurs in combination with K103N. By itself it causes intermediate resistance to NVP, DLV, and EFV, and 2 to 4-fold decreased ETR susceptibility. In combination with K103N it causes high-level resistance to NVP, DLV, and EFV and 10 to 20-fold decreased ETR susceptibility. $listMutsIn{100(NOT I)} is a highly unusual mutation at this position. |
| 101 | K | E | K101E causes intermediate resistance to NVP and DLV and low-level resistance to EFV and ETR. |
| 101 | K | HN | K101H/N are rare NNRTI-associated mutations with uncertain phenotypic and clinical effects. K101H was weakly associated with a decreased ETR response in the DUET studies. |
| 101 | K | P | K101P nearly always occurs with K103N and in this setting causes high-level resistance to NVP, DLV, and EFV. By itself K101P reduces ETR susceptibility 6-fold. |
| 101 | K | Q | K101Q is weakly associated with NNRTI therapy and minimally reduces susceptibility to each of the NNRTIs. |
| 101 | K | R | K101R is an uncommon polymorphism that has not been associated with decreased NNRTI susceptibility. |
| 101 | K | NOT EHNPQR | K101E/P/N/H/Q are NNRTI-selected mutations. $listMutsIn{101(NOT EHNPQR)} is a highly unusual mutation at this position. |
| 103 | K | EQ | K103E/Q are rare mutations that have not been associated with resistance to the current NNRTIs. |
| 103 | K | N | K103N causes high-level resistance to NVP, DLV, and EFV. By itself it has no effect on ETR susceptibility. However, it has a synergistic effect with L100I and possibly K101P on ETR susceptibility. |
| 103 | K | R | K103R occurs in about 1%-2% of untreated persons and by itself has no effect on NNRTI susceptibility. However, the combination of K103R + V179D, reduces NVP, DLV, and EFV susceptibility by about 15-fold. |
| 103 | K | S | K103S causes high-level resistance to NVP and intermediate/high-level resistance to DLV and EFV. |
| 103 | K | TH | K103T/H are rare mutations that appear to be associated with intermediate/high-level resistance to NVP, DLV, and EFV. |
| 103 | K | NOT EHNQRST | K103N/S/T/H are NNRTI-resistance mutations. K103R/E/Q are variants that usually do not cause NNRTI resistance. $listMutsIn{103(NOT EHNQRST)} is a highly unusual mutation at this position. |
| 106 | V | A | V106A causes high-level resistance to NVP and DLV, and low/intermediate resistance to EFV. Its effect on ETR, if any, appears to be minimal. |
| 106 | V | I | V106I is a common polymorphism that was associated with decreased ETR response in the DUE study. However, it does not decrease NNRTI susceptibility. |
| 106 | V | L | V106L is a rare polymorphism that does not appear to be associated with NNRTI resistance. |
| 106 | V | M | V106M causes high-level resistance to NVP, EFV, and DLV but does not appear to decrease ETR susceptibility except as a marker of past NNRTI therapy. |
| 106 | V | NOT AIML | V106A/M are NNRTI-resistance mutations. V106I/L are polymorphisms that do not appear to cause NNRTI resistance. $listMutsIn{106(NOT AIML)} is a highly unusual mutation at this position. |
| 108 | V | I | V108I causes low-level reductions in susceptibility to each of the NNRTIs except ETR. It occasionally occurs in the absence of NNRTI therapy. |
| 108 | V | NOT I | V108I causes low-level reductions in susceptibility to each of the NNRTIs except ETR. It occasionally occurs in the absence of NNRTI therapy. $listMutsIn{108(NOT I)} is a highly unusual mutation at this position. |
| 138 | E | A | E138A is a polymorphism that has been recently added to the list of mutations associated with decreased ETR response in the DUET studies. |
| 138 | E | G | E138G is a rare mutation that has been reported to emerge in patients with ETR failure. It may contribute to decreased ETR susceptibility in combination with other mutations. |
| 138 | E | K | E138K is selected in vitro by ETR and reduces its susceptibility by about 5-fold. E138K reduces to susceptibility other NNRTIs by about 2 to 5-fold. |
| 138 | E | Q | E138Q is weakly associated with NNRTI therapy. It may contribute to decreased NNRTI susceptibility in certain genetic contexts. |
| 138 | E | NOT AGKQ | E138AGKQ are weakly assocated with decreased ETR suscepitibility. $listMutsIn{138(NOT AGKQ)} is an unusual mutation at this position. |
| 179 | V | DE | V179D/E cause low-level reductions in susceptibility to NVP, EFV, and DLV. V179D occurs in about 1% of untreated persons and reduces the susceptibility of each NNRTI by about 2-fold. The combination of K103R + V179D reduces the susceptibility of NVP, DLV, and EFV by about 15-fold; the combination's effect on ETR is not known. V179D was associated with a decreased response to ETR in the DUET studies. |
| 179 | V | F | V179F nearly always occurs in combination with Y181C. By itself, V179F has no effect on ETR susceptibility but in combination with Y181C, it reduces ETR susceptibility >100-fold and causes low-level EFV resistance. It is selected in vivo by ETR. |
| 179 | V | I | V179I is a common polymorphism which occurs more commonly in NNRTI-treated isolates. However, it does not reduce NNRTI susceptibility. |
| 179 | V | T | V179T is a rare mutation that was weakly associated with a decreased response to ETR in the DUET studies. It has no apparent effect on NNRTI susceptibility |
| 179 | V | NOT DEFIT | $listMutsIn{V179(NOT DEFIT)} is an unusual mutation at this position. |
| 181 | Y | CIV | Y181C/I/V cause high-level resistance to NVP and DLV and low-level resistance to EFV. Y181C/I/V reduces ETR susceptibility by 5 to 15-fold and provide the mutational foundation for the development of higher levels of ETR resistance. Y181C increases susceptibility to AZT and TDF. |
| 181 | Y | S | Y181C/I/V cause high-level resistance to NVP and DLV and low-level resistance to EFV. Y181C/I/V reduces ETR susceptibility by 5 to 15-fold and provide the mutational foundation for the development of higher levels of ETR resistance. Y181S is a rare NNRTI-selected mutation that causes intermediate-high resistance to NVP and DLV. Few data are available for EFV and ETR. |
| 181 | Y | NOT CISV | Y181C/I/V cause high-level resistance to NVP and DLV and low-level resistance to EFV. Y181C/I/V reduces ETR susceptibility by 5 to 15-fold and provide the mutational foundation for the development of higher levels of ETR resistance. $listMutsIn{181(NOT CISV)} is a highly unusual mutation at this position. |
| 188 | Y | C | Y188C causes high-level resistance to NVP and low-level resistance to EFV and DLV; its effect on ETR is not known. |
| 188 | Y | F | Y188F is a rare mutation at this position of uncertain significance. It is often an artifact of the two-base pair change required for the emergence of Y188L. |
| 188 | Y | H | Y188H causes intermediate resistance to NVP, EFV, and DLV and has been selected in vitro by ETR. |
| 188 | Y | L | Y188L causes high-level resistance to NVP and EFV, intermediate resistance to DLV, and potentially low-level resistance to ETR. |
| 188 | Y | NOT CHLF | Y188L/H/C are NNRTI-resistance mutations. $listMutsIn{188(NOT CHLF)} is a highly unusual mutation at this position. |
| 190 | G | A | G190A causes high level resistance to NVP, intermediate resistance to EFV, and increased DLV susceptibility. It has no effect on ETR susceptibility but was associated with a decreased response to ETR in the DUET studies. |
| 190 | G | CTV | G190C/T/V are rare mutations that cause high-level resistance to NVP and EFV and increased susceptibility to DLV. Their effect on ETR is not known. |
| 190 | G | EQ | G190E/Q cause high-level resistance to NVP and EFV and intermediate resistance to DLV. G190E + Y181C is associated with >100-fold decreased ETR susceptibility. |
| 190 | G | S | G190S causes high-level resistance to NVP and EFV and increases DLV susceptibility. Although it was on the list of 13 mutations associated with decreased ETR response in the DUET studies, it does not appear to decrease ETR susceptibility. |
| 190 | G | NOT ACEQSTV | G190A/S/E/Q/T/V/C are NNRTI-resistance mutations. $listMutsIn{190(NOT ACEQSTV)} is a highly unusual mutation at this position. |
| 221 | H | Y | H221Y is an uncommon NNRTI-associated mutation. Its phenotypic effect on current NNRTIs has not been studied. |
| 221 | H | NOT Y | H221Y is an uncommon NNRTI-associated mutation. Its phenotypic effect on current NNRTIs has not been studied. $listMutsIn{221(NOT Y)} is a highly unusual mutation at this position. |
| 225 | P | H | P225H increases EFV resistance when present in combination with K103N. |
| 225 | P | NOT H | P225H increases EFV resistance when present in combination with K103N. $listMutsIn{225(NOT H)} is a highly unusual mutation at this position. |
| 227 | F | C | F227C is a rare mutation which which has emerged in vitro with ETR. It has been associated with a wide range in phenotypic resistance to each of the NNRTIs. |
| 227 | F | L | F227L usually occurs in combination with V106A and in this setting is associated with high level resistance to NVP and intermediate resistance to DLV and EFV. Its effect on ETR is not known. |
| 227 | F | NOT CL | F227LC are NNRTI-associated mutations. $listMutsIn{F227(NOT CL)} is a highly unusual mutation at this position. |
| 230 | M | L | M230L causes intermediate-to-high-level resistance to each of the NNRTIs. It has been selected in vitro by ETR and reduces ETR susceptibility by about 3 to 10-fold depending on the assay. |
| 230 | M | NOT L | M230L causes intermediate-to-high-level resistance to each of the NNRTIs. $listMutsIn{230(NOT L)} is a highly unusual mutation at this position. |
| 234 | L | I | L234I has been selected in vitro by ETR and it acts synergistically with Y181C to reduced susceptibility. Its clinical significance and effect on other NNRTIs is not known. |
| 234 | L | NOT I | L234I is an uncommon NNRTI associated mutation. $listMutsIn{234(NOT I)} is a highly unusual mutation at this position. |
| 236 | P | L | P236L causes high-level DLV resistance. |
| 236 | P | NOT L | P236L causes high-level DLV resistance. $listMutsIn{236(NOT L)} is a highly unusual mutation at this position. |
| 238 | K | N | K238T is an NNRTI-selected mutations that usually occur in combination with K103N in which case it causes high-level resistance to NVP, EFV, and DLV. Its effect on ETR is not known. K238N is a rarer NNRTI-selected mutation at this position. Its phenotypic effect is not known. |
| 238 | K | R | K238R is a naturally occurring variant that is common in some non-B subtypes and does not reduce NNRTI susceptibility. |
| 238 | K | T | K238T is an NNRTI-selected mutations that usually occur in combination with K103N in which case it causes high-level resistance to NVP, EFV, and DLV. Its effect on ETR is not known. |
| 238 | K | NOT NRT | K238T/N are NNRTI-associated mutations. K238R is a common polymorphism that is not associated with NNRTIs. $listMutsIn{238(NOT NRT)} is a highly unusual mutation at this position. |
| 318 | Y | F | Y318F is an uncommon mutation that causes high-level DLV resistance and low/intermediate NVP resistance. |
| 318 | Y | NOT F | Y318F is an uncommon mutation that causes high-level DLV resistance and low/intermediate NVP resistance. $listMutsIn{318(NOT F)} is a highly unusual mutation at this position. |
