rs121918116
A SNP in the EPOR gene on chromosome 19. Its most notable genotype is C;T: benign erythrocytosis, resulting in more red blood cells
- Gene
- EPOR
- Location
- Chr 1911,378,194 (GRCh38)
- Highest magnitude
- 3.0Important
- Tested on
- AncestryDNA
Genotypes
Plus strand, as in 23andMe and AncestryDNA files.
SNPedia records rs121918116 on the minus strand: (A;G), (G;G). Magnitude rates how notable a genotype is from 0 to 10, not how risky it is.
Notes
From SNPedia
Show notes, about 170 words
rs121918116, also known as c.1317G>A, p.Trp439Ter or W439X, is a rare mutation in the EPOR erythropoietin receptor gene on chromosome 19. In a large Finnish family with autosomal dominant erythrocytosis (an increased number of circulating red blood cells), researchers found the rs121918116(G) mutation; the phenotype was mild in all individuals, and one individual (Eero Mantyranta) won 3 Olympic gold medals in cross-country skiing, presumably due in part to his body's ability to carry ~50% more oxygen than average.
C;T
Discovered quite a while ago (1993; ), this mutation originally found in Finnish and Swedish Laplanders results in a mild familial (and dominant) form of erythrocytosis. Lifespan is unaffected, and in fact, the higher hematocrit levels (based on having more red blood cells) appears to predispose these individuals to perform better in endurance sports. Perhaps the best known example of this is the Olympic cross-country skier, Eero Mantyranta.
C;C
but the rare form seems beneficial
References
Source and license
Adapted from rs121918116 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 Its entries can be incomplete, out of date or wrong, and nothing here is a diagnosis or medical advice.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.