rs9951307

A SNP in the AQP4 gene on chromosome 18. Its most notable genotype is A;A: normal

Gene
AQP4
Location
Chr 1826,850,565 (GRCh38)
Highest magnitude
0.0Typical
Tested on
23andMe, AncestryDNA, FamilyTreeDNA
Minor allele frequency
30%

Genotypes

As shown in 23andMe and AncestryDNA files.

  1. A;AMost notableNot ratednormalTypical · 0.052% of people
  2. A;GGood0.10 decreased risk for brain edema after a strokeTypical · 0.039% of people
  3. G;GNot rated0.10 decreased risk for brain edema after a strokeTypical · 0.09% of people

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 11 HapMap populations.

  • AverageA;A 52% A;G 39% G;G 9%
  • European ancestry (Utah)A;A 44% A;G 40% G;G 16%
  • Han Chinese (Beijing)A;A 61% A;G 34% G;G 5%
  • Japanese (Tokyo)A;A 71% A;G 27% G;G 3%
  • Yoruba (Nigeria)A;A 37% A;G 48% G;G 15%
  • African ancestry (Southwest US)A;A 39% A;G 51% G;G 11%
  • Chinese (Denver)A;A 79% A;G 19% G;G 2%
  • Gujarati IndianA;A 49% A;G 44% G;G 8%
  • Luhya (Kenya)A;A 40% A;G 46% G;G 14%
  • Mexican ancestry (Los Angeles)A;A 69% A;G 26% G;G 5%
  • Maasai (Kenya)A;A 47% A;G 45% G;G 9%
  • TuscanA;A 42% A;G 49% G;G 9%

Conditions, medicines and genes

Notes

From SNPedia

Notes

rs9951307is a SNP in the aquaporin-4 (AQP4) gene; the corresponding protein is the main water channel in the brain and is implicated in the development of brain edema after an ischemic stroke. A study of 41 patients with middle cerebral artery occlusion with and without severe brain edema found that rs9951307 was associated with severe brain edema (dominant model, p=0.01; OR, 0.10, CI: 0.02 to 0.49 for the protective (G) allele).

Source and license

Adapted from rs9951307 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 Its entries can be incomplete, out of date or wrong, and nothing here is a diagnosis or medical advice.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.