rs16990018
A SNP in the PRNP gene on chromosome 20. Its most notable genotype is G;G.
- Gene
- PRNP
- Location
- Chr 204,699,732 (GRCh38)
- Highest magnitude
- 2.0Worth knowing
- Tested on
- 23andMe, AncestryDNA
- Minor allele frequency
- 2%
Genotypes
As shown in 23andMe and AncestryDNA files.
- A;AGoodPrP Codon 171 Asn - Non-pathogenic variant
- A;GNot ratedPrP 171 N/S Heterozygote - Unknown significance
- G;GMost notableNot ratedNo summary available.
On SNPedia: (A;A), (A;G), (G;G). Magnitude rates how notable a genotype is from 0 to 10, not how risky it is.
Frequency
Share of each genotype in 9 HapMap populations.
- AverageA;A 94% A;G 6% G;G <1%
- European ancestry (Utah)A;A 100% A;G 0% G;G 0%
- Han Chinese (Beijing)A;A 97% A;G 3% G;G 0%
- Japanese (Tokyo)A;A 100% A;G 0% G;G 0%
- Yoruba (Nigeria)A;A 88% A;G 12% G;G 0%
- African ancestry (Southwest US)A;A 84% A;G 12% G;G 4%
- Gujarati IndianA;A 99% A;G 1% G;G 0%
- Luhya (Kenya)A;A 80% A;G 19% G;G <1%
- Mexican ancestry (Los Angeles)A;A 98% A;G 2% G;G 0%
- TuscanA;A 98% A;G 2% G;G 0%
Related
Other PRNP SNPs
- rs74315405C;TGerstmann–Straussler–Scheinker syndromeVery important
- rs74315401C;TGerstmann–Straussler–Scheinker syndromeVery important
- rs74315402C;TGerstmann–Straussler–Scheinker syndromeVery important
- rs74315406A;GGerstmann–Straussler–Scheinker syndromeVery important
- rs74315410G;TGerstmann–Straussler–Scheinker syndromeVery important
- rs74315413A;GGerstmann–Straussler–Scheinker syndromeVery important
- rs74315414A;CGerstmann–Straussler–Scheinker syndromeVery important
- rs74315415C;TGerstmann–Straussler–Scheinker syndromeVery important
Notes
From SNPedia
Notes
The importance of this codon has been reclassified based on further research. Normally Asn, the Asn171Ser variant was identified in a patient with Prion disease, , and further research indicated that it may be associated with temporal lobe epilepsy . However, more recent research has indicated that the N171S variant is present in healthy members of numerous populations, reaching penetrance of 11% in Biaka Pygmies and 5% in Jamaicans. Thus this polymorphism is considered of unknown significance.
A;G
This SNP indicates heterozygosity at Codon 171 of the Prion Protein. This SNP was recently determined to be more common than expected in healthy controls and so is now believed to be non-pathogenic.
References
Source and license
Adapted from rs16990018 on SNPedia, using a snapshot taken October 16, 2026. SNPedia content is shared under CC BY-NC-SA 3.0 US, and this page is shared under the same license.
SNPedia is a community-edited wiki. Its entries can be incomplete, out of date or wrong, and nothing here is a diagnosis or medical advice. Magnitude is a community rating of how interesting a genotype is, not a risk score.