rs855791

A SNP in the TMPRSS6 gene on chromosome 22. Its most notable genotype is G;G: normal

Gene
TMPRSS6
Location
Chr 2237,066,896 (GRCh38)
Highest magnitude
0.0Typical
Tested on
23andMe, AncestryDNA
Minor allele frequency
40%

Genotypes

Plus strand, as in 23andMe and AncestryDNA files.

  1. G;GMost notableNot ratednormalTypical · 0.043% of people
  2. A;GNot rated0.1 g/dL lower hemoglobin on averageTypical · 0.037% of people
  3. A;ABad0.2 g/dL lower hemoglobin on averageTypical · 0.020% of people

SNPedia records rs855791 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 11 HapMap populations.

  • AverageG;G 43% A;G 37% A;A 20%
  • European ancestry (Utah)G;G 35% A;G 47% A;A 18%
  • Han Chinese (Beijing)G;G 18% A;G 55% A;A 28%
  • Japanese (Tokyo)G;G 13% A;G 51% A;A 35%
  • Yoruba (Nigeria)G;G 80% A;G 19% A;A 1%
  • African ancestry (Southwest US)G;G 65% A;G 32% A;A 4%
  • Chinese (Denver)G;G 18% A;G 47% A;A 35%
  • Gujarati IndianG;G 21% A;G 42% A;A 38%
  • Luhya (Kenya)G;G 83% A;G 16% A;A <1%
  • Mexican ancestry (Los Angeles)G;G 24% A;G 40% A;A 36%
  • Maasai (Kenya)G;G 83% A;G 17% A;A 0%
  • TuscanG;G 31% A;G 46% A;A 23%

Other TMPRSS6 SNPs

All TMPRSS6 SNPs

Notes

From SNPedia

Show notes, about 120 words

rs855791, also known as V736A, is a SNP in the transmembrane protease, serine 6 TMPRSS6 gene. 2 studies totaling over 17,000 individuals have linked this SNP to various blood parameters, including iron status, erythrocyte volume, and hemoglobin levels.PMID 19820699, PMID 19820698 23andMe blog each rs855791(T) and each rs198846(G) led to an approximately 0.1 gram per deciliter (g/dL) decrease in hemoglobin levels. rs1799945(C) is a proxy for rs198846(G). Genetics and genomics of human ageing. Association of TMPRSS6 polymorphisms with ferritin, hemoglobin, and type 2 diabetes risk in a Chinese Han population. TMPRSS6, but not TF, TFR2 or BMP2 variants are associated with increased risk of iron-deficiency anemia.

Source and license

Adapted from rs855791 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 Its entries can be incomplete, out of date or wrong, and nothing here is a diagnosis or medical advice.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.