rs602662

A SNP in the FUT2 gene on chromosome 19. Its most notable genotype is A;A: Higher vitamin B12 levels

Gene
FUT2
Location
Chr 1948,703,728 (GRCh38)
Highest magnitude
2.0Worth knowing
Tested on
23andMe, AncestryDNA
Minor allele frequency
34%

Genotypes

As shown in 23andMe and AncestryDNA files.

  1. A;AMost notableGoodHigher vitamin B12 levelsWorth knowing · 2.017% of people
  2. G;GBadLower vitamin B12 levelsWorth knowing · 2.045% of people

On SNPedia: (A;A), (G;G). Magnitude rates how notable a genotype is from 0 to 10, not how risky it is.

Frequency

Share of each genotype in 10 HapMap populations.

  • AverageA;A 17% G;G 45%
  • European ancestry (Utah)A;A 35% G;G 19%
  • Han Chinese (Beijing)A;A 0% G;G 98%
  • Japanese (Tokyo)A;A 0% G;G 100%
  • Yoruba (Nigeria)A;A 27% G;G 19%
  • African ancestry (Southwest US)A;A 32% G;G 23%
  • Gujarati IndianA;A 4% G;G 58%
  • Luhya (Kenya)A;A 22% G;G 33%
  • Mexican ancestry (Los Angeles)A;A 10% G;G 35%
  • Maasai (Kenya)A;A 17% G;G 37%
  • TuscanA;A 26% G;G 27%

Other FUT2 SNPs

All FUT2 SNPs

Notes

From SNPedia

Notes

A;A

The reduced activity of the FUT2 enzyme with the A allele may decrease susceptibility to bacterial infection and indirectly lower the risk of vitamin B12 malabsorption, thereby resulting in higher vitamin B12 concentrations in A allele carriers. PMID 19303062

G;G

We found that the SNP rs602662 was significantly associated with the levels of vitamin B(12) (p value<0.0001). We also found that individuals adhering to a vegetarian diet with GG (homozygous major genotype) have significantly lower levels of vitamin B(12) in these individuals. PMID 23201895

References

Source and license

Adapted from rs602662 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 Its entries can be incomplete, out of date or wrong, and nothing here is a diagnosis or medical advice.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.