{{Rsnum
|rsid=2240017
|Gene=TBX21
|Chromosome=17
|position=47733553
|Orientation=minus
|ReferenceAllele=C
|MissenseAllele=G
|GMAF=0.04316
|Assembly=GRCh38
|GenomeBuild=38.1
|dbSNPBuild=141
|geno1=(C;C)
|geno2=(C;G)
|geno3=(G;G)
|Gene_s=TBX21
}}{{ population diversity
| geno1=(C;C)
| geno2=(C;G)
| geno3=(G;G)
| CEU | 0.0 | 0.0 | 100.0
| HCB | 2.2 | 17.8 | 80.0
| JPT | 6.8 | 13.6 | 79.5
| YRI | 0.0 | 0.0 | 100.0
| ASW | 0.0 | 0.0 | 0.0
| CHB | 2.2 | 17.8 | 80.0
| CHD | 0.0 | 0.0 | 0.0
| GIH | 0.0 | 0.0 | 0.0
| LWK | 0.0 | 0.0 | 0.0
| MEX | 0.0 | 0.0 | 0.0
| MKK | 0.0 | 0.0 | 0.0
| TSI | 0.0 | 0.0 | 0.0
| HapMapRevision=28
}}This SNP encodes a variation in the 33rd amino acid of the protein encoded by the [[TBX21]] gene. Although 95% or so of all Caucasians carry two copies of the [[rs2240017(G)]] allele, as oriented in dbSNP orientation, and are thus [[rs2240017(G;G)]] homozygotes, a few individuals are [[rs2240017(C;G)]] heterozygotes. These heterozgotes are reported to improve better over time in response to corticosteroid treatment for [[asthma]] than the [[rs2240017(G;G)]] homozygotes. So far, studies have not linked, however, this SNP to any change in the overall risk of [[asthma]] itself. {{PMID|15604153|OA=1
}}

Although the effect observed was strong, in that treating [[rs2240017(C;G)]] heterozygotes ultimately (over 4 years) yields average airway responsiveness in the normal range (i.e. in the same range as for nonasthmatics), the authors point out that the relatively small number of heterozygous children studied indicates that a larger study is warranted to ensure reproducibility. {{PMID|15604153|OA=1
}}

It is also unknown whether the effect is limited to the particular corticosteroid used ([[budesonide]], aka [[Rhinocort]]) in this study. This is thought to be unlikely, though, given the general nature of the drug.
{{ neighbor
| rsid = 2074190
| distance = 291
}}

{{PharmGKB
|RSID=rs2240017
|Name_s=TBX21:H33Q
|Gene_s=TBX21
|Feature=Exon/NonSyn
|Evidence=PubMed ID:15604153
|Annotation=This variant is associated with improved response to inhaled corticosteroids for asthma patients
|Drugs=budesonide; nedocromil
|Drug Classes=
|Diseases=Asthma
|Curation Level=Curated
|PharmGKB Accession ID=PA162181147
}}

{{PMID Auto
|PMID=18045485
|Title=The candidate genes TAF5L, TCF7, PDCD1, IL6 and ICAM1 cannot be excluded from having effects in type 1 diabetes.
|OA=1
}}

{{on chip | 23andMe v3}}
{{on chip | 23andMe v4}}
{{on chip | HumanOmni1Quad}}