rs492602

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

Gene
FUT2
Location
Chr 1948,703,160 (GRCh38)
Highest magnitude
1.5Minor
Tested on
23andMe, AncestryDNA
Minor allele frequency
32%

Genotypes

Plus strand, as in 23andMe and AncestryDNA files.

  1. G;GMost notableNot ratedHigher B12 levels in womenMinor · 1.516% of people
  2. A;GGoodNormal B12 levelsMinor · 1.038% of people
  3. A;AGoodNormal B12 levelsMinor · 1.046% of people

SNPedia records rs492602 on the minus strand: (C;C), (C;T), (T;T). 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.

  • AverageG;G 16% A;G 38% A;A 46%
  • European ancestry (Utah)G;G 30% A;G 46% A;A 24%
  • Han Chinese (Beijing)G;G 0% A;G 2% A;A 98%
  • Japanese (Tokyo)G;G 0% A;G 0% A;A 100%
  • Yoruba (Nigeria)G;G 27% A;G 54% A;A 19%
  • African ancestry (Southwest US)G;G 30% A;G 47% A;A 23%
  • Gujarati IndianG;G 4% A;G 38% A;A 58%
  • Luhya (Kenya)G;G 22% A;G 46% A;A 33%
  • Mexican ancestry (Los Angeles)G;G 9% A;G 55% A;A 36%
  • Maasai (Kenya)G;G 15% A;G 47% A;A 38%
  • TuscanG;G 24% A;G 48% A;A 28%

Other FUT2 SNPs

All FUT2 SNPs

Notes

From SNPedia

Notes

From : We identified a strong association (p = 5.36 x 10(-17)) between rs492602 in the FUT2 gene and plasma vitamin B(12) levels in a genome-wide scan (n = 1,658) and an independent replication sample (n = 1,059) from the Nurses' Health Study. Women homozygous for the rs492602(C) allele (in dbSNP orientation) had higher B(12) levels. This allele is in strong linkage disequilibrium with the FUT2 nonsecretor variant encoding W143X, suggesting a plausible mechanism for altered B(12) absorption and plasma levels.

Source and license

Adapted from rs492602 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 Its entries can be incomplete, out of date or wrong, and nothing here is a diagnosis or medical advice.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.