rs661
A SNP in the PSEN1 gene on chromosome 14. Its most notable genotype is A;A: early onset Alzheimer's disease
- Gene
- PSEN1
- Location
- Chr 1473,217,225 (GRCh38)
- Highest magnitude
- 9.0Very important
- Tested on
- 23andMe, AncestryDNA
Genotypes
As shown in 23andMe and AncestryDNA files.
- A;AMost notableBadearly onset Alzheimer's disease
- A;GBadearly-onset Alzheimers disease
- G;GGoodnormal
On SNPedia: (A;A), (A;G), (G;G). Magnitude rates how notable a genotype is from 0 to 10, not how risky it is.
Related
Conditions, medicines and genes
Other PSEN1 SNPs
- rs63749885C;Tearly-onset Alzheimers diseaseVery important
- rs63749891C;Gearly-onset Alzheimers diseaseVery important
- rs63750577C;Tearly-onset Alzheimers diseaseVery important
- rs63750599C;Tearly-onset Alzheimers diseaseVery important
- rs63750815G;Tearly-onset Alzheimers diseaseVery important
- rs63750886C;Gearly-onset Alzheimers diseaseVery important
- rs63750900A;Gearly-onset Alzheimers diseaseVery important
- rs63751037A;Gearly-onset Alzheimers diseaseVery important
Notes
From SNPedia
Notes
rs661, also known as C410Y or Cys410Tyr, is a SNP in the presenilin 1 PSEN1 gene. The rare rs661(A) allele is considered causative for early-onset Alzheimer's disease. 23andMe calls this i5007546
A;G
See discussion at rs661.
Source and license
Adapted from rs661 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 Its entries can be incomplete, out of date or wrong, and nothing here is a diagnosis or medical advice.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.