rs63749884
A SNP in the PSEN2 gene on chromosome 1. Its most notable genotype is A;G: early-onset Alzheimer's disease; penetrance not 100%
- Gene
- PSEN2
- Location
- Chr 1226,888,979 (GRCh38)
- Highest magnitude
- 8.0Very important
- Tested on
- 23andMe, AncestryDNA
Genotypes
As shown in 23andMe and AncestryDNA files.
On SNPedia: (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 PSEN2 SNPs
- rs28936379A;Gearly-onset Alzheimers diseaseVery important
- rs28936380C;Gearly-onset Alzheimer's diseaseVery important
- rs63749851A;CEarly-onset Alzheimer's diseaseVery important
- rs63750215A;Tearly-onset Alzheimer's diseaseVery important
- rs61761208A;TEarly-onset Alzheimer's mutation (reported)Very important
- rs63750666C;Tearly-onset Alzheimer's disease; penetrance unclearVery important
- rs200754713A;GFrontotemporal dementia (reported)Very important
- rs367855127C;TPossible early-onset Alzheimer's disease mutation; see discussionVery important
Notes
From SNPedia
Notes
rs63749884, also known as c.717G>A, M239I or Met239Ile, is a SNP in the presenilin 2 PSEN2 gene. Inherited as an autosomal dominant, the rare rs63749884(A) allele is considered causative for early-onset Alzheimer's disease; see . However, only three of the five individuals in the family studied who carried this mutation developed Alzheimer's; the other two did not. The penetrance of this mutation is therefore clearly not 100%, for reasons that are unknown.
A;G
The rs63749884(A) allele is reported to lead to early-onset Alzheimer's disease. However, not all carriers of this allele develop Alzheimers for reasons that are unknown.
Source and license
Adapted from rs63749884 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 Its entries can be incomplete, out of date or wrong, and nothing here is a diagnosis or medical advice.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.