{{Rsnum
|rsid=243588
|Gene=C21orf91-OT1
|Chromosome=21
|position=17782249
|Orientation=minus
|GMAF=0.4991
|Gene_s=C21orf91-OT1
|Assembly=GRCh38
|GenomeBuild=38.1
|dbSNPBuild=141
|geno1=(A;A)
|geno2=(A;G)
|geno3=(G;G)
}}{{ population diversity
| geno1=(A;A)
| geno2=(A;G)
| geno3=(G;G)
| CEU | 31.5 | 51.4 | 17.1
| HCB | 15.9 | 50.0 | 34.1
| JPT | 26.9 | 50.9 | 22.2
| YRI | 37.0 | 43.8 | 19.2
| ASW | 27.3 | 60.0 | 12.7
| CHB | 15.9 | 50.0 | 34.1
| CHD | 0.0 | 0.0 | 0.0
| GIH | 24.5 | 44.9 | 30.6
| LWK | 22.0 | 53.2 | 24.8
| MEX | 36.2 | 36.2 | 27.6
| MKK | 18.1 | 49.0 | 32.9
| TSI | 19.8 | 52.5 | 27.7
| HapMapRevision=28
}}{{PMID|22039568|OA=1
}} C21orf91 genotypes correlate with herpes simplex labialis (cold sore) frequency: description of a cold sore susceptibility gene.

{{on chip | 23andMe v1}}
{{on chip | 23andMe v2}}
{{on chip | 23andMe v3}}
{{on chip | 23andMe v4}}
{{on chip | Illumina Human 1M}}