rs638405

A SNP in the BACE1 gene on chromosome 11. Its most notable genotype is G;G: 2x increased ALZ risk in ApoE4 carriers

Gene
BACE1
Location
Chr 11117,293,108 (GRCh38)
Highest magnitude
2.0Worth knowing
Tested on
AncestryDNA
Minor allele frequency
49%

Genotypes

As shown in 23andMe and AncestryDNA files.

  1. C;CNot ratednormal riskTypical · 0.023% of people
  2. C;GNot ratednormal riskTypical · 0.045% of people
  3. G;GMost notableBad2x increased ALZ risk in ApoE4 carriersWorth knowing · 2.032% of people

On SNPedia: (C;C), (C;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 4 HapMap populations.

  • AverageC;C 23% C;G 45% G;G 32%
  • European ancestry (Utah)C;C 44% C;G 48% G;G 8%
  • Han Chinese (Beijing)C;C 13% C;G 53% G;G 33%
  • Japanese (Tokyo)C;C 14% C;G 30% G;G 57%
  • Yoruba (Nigeria)C;C 21% C;G 50% G;G 29%

Conditions, medicines and genes

Other BACE1 SNPs

All BACE1 SNPs

Notes

From SNPedia

Notes

rs638405, a SNP also known as Val262, is located in exon 5 of the BACE1 gene, and is associated in some studies (but not others) with increased risk for late-onset Alzheimer's disease. The only statistically robust associations with increased risk for Alzheimer's disease appear to be seen in individuals who are also ApoE4 carriers. For example, a meta-analysis pooling 4 Chinese and 1 Korean study found a significant association between the (G;G) - in orientation to dbSNP, not as published - genotype and Alzheimer's disease in ApoE4+ groups with an odds ratio of 1.99 (CI: 1.319-3.018, p=0.0044).

Source and license

Adapted from rs638405 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 Its entries can be incomplete, out of date or wrong, and nothing here is a diagnosis or medical advice.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.