<!--#if expr="$title" --> <!--#echo var="title" --> <!--#else --> HIV Drug Resistance Database <!--#endif -->
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.

MARVEL on RT mutations at position 221


HIVdb Algorithm: Comments & Scores
  • H221Y is a nonpolymorphic accessory NNRTI-selected mutation that frequently occurs in combination with Y181C. Alone it has minimal detectable effects on NNRTI susceptibility. It is frequently selected in patients receiving RPV (Rimsky 2012, Tibotec 2012).

MutationEFVNVPETRRPV
H221Y10101010
Footnote:Mutation scores on the left are derived from published literature linking mutations and ARVs (the complete details can be found in the HIVdb Release Notes).
Genotype-treatment correlation
Mutation frequency according to subtype and drug-class experience.
The frequency of each mutation at position 221 according to subtype and drug-class experience. Data are shown for the 8 most common subtypes. The number of persons in each subtype/treatment category is shown beneath the subtype. Mutations occurring at a frequency >0.5% are shown. Each mutation is also a hyper-link to a separate web page with information on each isolate, including literature references with PubMed abstracts, the GenBank accession number, and complete sequence and treatment records.

PosWTNRTI (but no NNRTI) Treated Persons NNRTI Treated Persons
A
205
B
4133
C
551
D
127
F
82
G
146
AE
330
AG
78
 
A
635
B
10958
C
3765
D
419
F
275
G
874
AE
1679
AG
824
221 H Y 1.1    Y 1.3     Y 3.7 Y 4.0 Y 4.3 Y 3.8 Y 4.9 Y 6.2 Y 11 Y 7.8
Footnote: The query page Mutation Prevalence According to Subtype and Treatment to examine the frequency of all mutations according to subtype and treatment; The program HIVSeq provides similar output for mutations in user-submitted sequences; A complete description of the program that generates these tables can be found at Rhee et al AIDS 2006.
 

Mutation frequency according to treatment with individual ARVs.
The first row shows the frequency of the mutation in persons who are RTI-naive (indicated in green). The second row shows the frequency of the mutation in persons who have received one or more NRTIs (No NNRTIs). The third row shows the frequency of the mutation in persons who have received one or more NNRTIs (+/- NRTIs). The following rows show the frequency of the mutation in persons who have received only a single NNRTI. Mutation rates that differ significantly between treated and untreated isolates are indicated in yellow.
MutationNRTINNRTINumSeqNumMut% Mutantp
H221C00503500  
H221C>=1>=025160190.000.000
H221CAZT>=04170  
H221CDDI>=0520  
H221CD4T>=0530  
H221CABC>=050  
H221CD4T+3TC>=0322910.000.065
H221CAZT+3TC>=0228530.100.000
H221CD4T+DDI>=045510.200.000
H221CAZT+DDI>=05530  
H221CABC+3TC>=02810  
H221CTDF+3TC>=03730  
H221CTDF+FTC>=03510  
MutationNRTINNRTINumSeqNumMut% Mutantp
H221L005035080.00 
H221L>=1>=025160220.000.000
H221LAZT>=04170  
H221LDDI>=0520  
H221LD4T>=0530  
H221LABC>=050  
H221LD4T+3TC>=0322970.200.000
H221LAZT+3TC>=0228520.000.098
H221LD4T+DDI>=045520.400.000
H221LAZT+DDI>=05530  
H221LABC+3TC>=02810  
H221LTDF+3TC>=03730  
H221LTDF+FTC>=03510  
MutationNRTINNRTINumSeqNumMut% Mutantp
H221P0050350100.00 
H221P>=1>=02516060.000.929
H221PAZT>=04170  
H221PDDI>=0520  
H221PD4T>=0530  
H221PABC>=050  
H221PD4T+3TC>=0322910.000.836
H221PAZT+3TC>=0228520.000.165
H221PD4T+DDI>=045520.400.000
H221PAZT+DDI>=055310.100.268
H221PABC+3TC>=02810  
H221PTDF+3TC>=03730  
H221PTDF+FTC>=03510  
MutationNRTINNRTINumSeqNumMut% Mutantp
H221Q005035090.00 
H221Q>=1>=02516040.000.920
H221QAZT>=04170  
H221QDDI>=0520  
H221QD4T>=0530  
H221QABC>=050  
H221QD4T+3TC>=032290  
H221QAZT+3TC>=022850  
H221QD4T+DDI>=04550  
H221QAZT+DDI>=05530  
H221QABC+3TC>=02810  
H221QTDF+3TC>=03730  
H221QTDF+FTC>=035110.200.100
MutationNRTINNRTINumSeqNumMut% Mutantp
H221R0050350100.00 
H221R>=1>=02516010.000.166
H221RAZT>=04170  
H221RDDI>=0520  
H221RD4T>=0530  
H221RABC>=050  
H221RD4T+3TC>=032290  
H221RAZT+3TC>=0228510.000.975
H221RD4T+DDI>=04550  
H221RAZT+DDI>=05530  
H221RABC+3TC>=02810  
H221RTDF+3TC>=03730  
H221RTDF+FTC>=03510  
MutationNRTINNRTINumSeqNumMut% Mutantp
H221Y0050350380.00 
H221Y>=1>=02516014695.800.000
H221YAZT>=04170  
H221YDDI>=05211.900.022
H221YD4T>=05311.800.023
H221YABC>=05360.000.000
H221YD4T+3TC>=032293159.700.000
H221YAZT+3TC>=02285793.400.000
H221YD4T+DDI>=0455245.200.000
H221YAZT+DDI>=055391.600.000
H221YABC+3TC>=0281165.600.000
H221YTDF+3TC>=0373205.300.000
H221YTDF+FTC>=0351123.400.000
Footnote: About one-half of the untreated isolates belong to non-subtype B isolates; About 20% of the treated isolates belong to non-subtype B isolates; A page containing summaries for all of the mutations at this position can be found here.

Genotype-phenotype correlation
Phenotypes of top 10 common patterns of drug resistance mutations with mutations at position 221.
Mutation pattern data is not available for H221.

A complete summary of additional in vitro susceptibility data for viruses with H221 obtained using other assays including the Antivirogram can be found here.

 

Phenotypic coefficients using machine learning
Least Square Regression (LSR) was used to learn the relative contribution of each mutation to the fold decrease in susceptibility for an ARV. The figure on the left (click to enlarge the figure) shows the regression coefficients (which correlate with the contribution to resistance) for the 24 nonpolymorphic NNRTI-resistance mutations shown to contribute decreased susceptibility to at least one NNRTI. A complete description of the method that generates this figure can be found at Rhee et al PNAS 2006.