rs10741657
Turning vitamin D into the usable form
What this position does
CYP2R1 is the liver enzyme that activates vitamin D after your skin makes it. It is the second of the two strongest common influences on your measured level.
Skin. Shaped by making vitamin d from weak northern sun. This is one of the variants that differs sharply between human populations, because something in the environment made one version worth having.
Sunlight and vitamin D
Skin has to let in enough ultraviolet light to make vitamin D, and block enough to protect the folate in your blood. The right answer depends entirely on where you live, so it changed every time people moved.
What changed: Industry, roughly the last two centuries. Indoor work, heated buildings, refined food, cheap salt and sugar, tobacco at scale, and a collapse in infectious disease. This is where most of the deals in your genome came undone.
Why it spread: well established. The environmental pressure behind this variant is documented and not in serious dispute.
Spiral Staircase, chapter 19: The Largest Organ Spiral Staircase is written by the same author as this site.
What each result means
| If you carry | What it means |
|---|---|
| No copies of the effect version AA | You have the higher-level version on both copies Associated with higher measured vitamin D. |
| One copy AG | You carry one lower-level copy Associated with somewhat lower measured vitamin D. |
| Two copies GG | You carry two lower-level copies Associated with the lowest average measured vitamin D at this position. |
How common each version is
How many people carry each result
How to find out which you have
If you have taken a test with 23andMe, AncestryDNA, MyHeritage, Family Tree DNA, TellMeGen or Living DNA, this position is very likely already in the raw data file they gave you. You do not need another test.
One thing to watch if you look it up by hand: testing companies report some positions from one DNA strand and some from the other, and the file does not say which. Read the letters as they appear and you will get the opposite of the truth for some positions. Sequencings resolves that automatically.
Source
Wang et al., Common genetic determinants of vitamin D insufficiency, The Lancet (2010)
Coordinates and allele pair verified against Ensembl GRCh37. Direction of effect verified against VEP protein consequences or 1000 Genomes population frequency. Category: Population adaptation.
Where this fits
Common questions
What is rs10741657?
rs10741657 is a position in the CYP2R1 gene on chromosome 11. CYP2R1 is the liver enzyme that activates vitamin D after your skin makes it. It is the second of the two strongest common influences on your measured level.
What does it mean if I have GG at rs10741657?
You carry two lower-level copies. Associated with the lowest average measured vitamin D at this position.
What does it mean if I have AA at rs10741657?
You have the higher-level version on both copies. Associated with higher measured vitamin D.
How do I find out my rs10741657 genotype?
If you have taken a home DNA test, this position is very likely in the raw data file you were given. Sequencings reads that file in your browser without uploading it, and resolves which DNA strand each position was reported from, which is the step most manual lookups get wrong.
This is reference information, not medical advice, and not a diagnosis. See the medical disclaimer. Category: Population adaptation.