rs1800414
Lighter skin, the East Asian route
What this position does
Europe and East Asia both evolved lighter skin after moving away from the tropics, and they did it with different genes. This is the East Asian one. It is a clean demonstration that the same environmental problem was solved twice, independently.
Skin. Shaped by sunlight and vitamin d at high latitude. 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 TT | You do not carry the East Asian lightening variant Absent, which is the case for essentially everyone of European or African descent. |
| One copy CT | You carry one copy One copy of a variant carried by around half of people in East Asia and almost nobody outside it. |
| Two copies CC | You carry two copies Two copies, associated with lighter skin. This is the common genotype across much of East Asia. |
How common each version is
| Ancestry group | C (the effect version) | |
|---|---|---|
| African | 0.1% | |
| American | 0.0% | |
| East Asian | 59.6% | |
| European | 0.0% | |
| South Asian | 0.4% |
1000 Genomes Project phase 3, via Ensembl, retrieved 2026-09-23. These groupings are coarse and flatten a great deal of internal diversity, particularly within Africa. A variant being common somewhere tells you where a piece of your ancestry probably comes from, and nothing else.
How many people carry each result
| Ancestry group | TT | CT | CC |
|---|---|---|---|
| African | 660 / 661 | 1 / 661 | 0 / 661 |
| European | 503 / 503 | 0 / 503 | 0 / 503 |
| East Asian | 75 / 504 | 257 / 504 | 172 / 504 |
| South Asian | 485 / 489 | 4 / 489 | 0 / 489 |
| American | 347 / 347 | 0 / 347 | 0 / 347 |
Counts of people, not modelled frequencies: every one of the 2,504 individuals sequenced by the 1000 Genomes Project phase 3, tallied by the genotype they carry. Deriving these from allele frequencies instead would assume random mating inside each group and undercount the homozygotes.
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
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 rs1800414?
rs1800414 is a position in the OCA2 gene on chromosome 15. Europe and East Asia both evolved lighter skin after moving away from the tropics, and they did it with different genes. This is the East Asian one. It is a clean demonstration that the same environmental problem was solved twice, independently.
What does it mean if I have CC at rs1800414?
You carry two copies. Two copies, associated with lighter skin. This is the common genotype across much of East Asia.
What does it mean if I have TT at rs1800414?
You do not carry the East Asian lightening variant. Absent, which is the case for essentially everyone of European or African descent.
How do I find out my rs1800414 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.