rs324640

A SNP in the CHRM2 gene on chromosome 7. Its most notable genotype is A;A.

Gene
CHRM2
Location
Chr 7137,004,249 (GRCh38)
Highest magnitude
0.0Typical
Tested on
23andMe, AncestryDNA, FamilyTreeDNA
Minor allele frequency
43%

Genotypes

As shown in 23andMe and AncestryDNA files.

  1. A;AMost notableNot ratedNo summary available.Typical · 0.017% of people
  2. A;GNot ratedNo summary available.Typical · 0.027% of people
  3. G;GNot ratedNo summary available.Typical · 0.056% 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 4 HapMap populations.

  • AverageA;A 17% A;G 27% G;G 56%
  • European ancestry (Utah)A;A 20% A;G 52% G;G 29%
  • Han Chinese (Beijing)A;A 0% A;G 11% G;G 89%
  • Japanese (Tokyo)A;A 0% A;G 11% G;G 90%
  • Yoruba (Nigeria)A;A 48% A;G 33% G;G 18%

Conditions, medicines and genes

Other CHRM2 SNPs

All CHRM2 SNPs

Notes

From SNPedia

Notes

SNPs in the SNAP25 gene were initially linked to intelligence but have failed to replicate . While now suspect, the original work can be found in and or this pdf poster show association between the CHRM2 gene and intelligence . In this study of ~300 Caucasians, the (G;G) genotype appeared to typically have a 4 point higher IQ than the (A;G) genotype, which had a 4 point higher IQ (on average) than the (A;A) genotype. A nearby SNP, rs324650, showed similar results to rs324640, and was in linkage disequilibrium (r2 = 0.90) with it.

Source and license

Adapted from rs324640 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 Its entries can be incomplete, out of date or wrong, and nothing here is a diagnosis or medical advice.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.