DNA Traits · Skin & sun
Ease of tanning (IRF4)
How easily skin tans in the sun.
What the research found
In the cited research, the T allele at rs12203592 was associated with lower self-reported ease of skin tanning in the studied cohorts.
- CC
- Tans more
- CT
- Middle
- TT
- Tans less
What the study found
In the study, each copy went with ease of suntan on a four step scale from never to strongly about 0.23 points lower on average.
- Evidence
- Genome-wide association with independent replication
- Who was studied
- European ancestry (UK Biobank with five replication cohorts, the Spanish GCAT cohort, and US nurses and health professionals)
How common each genotype is
| Region | CCTans more | CTMiddle | TTTans less |
|---|---|---|---|
| All regions2,504 people | 93% | 6% | <1% |
| Africa661 people | 98% | 1% | <1% |
| The Americas347 people | 86% | 13% | <1% |
| East Asia504 people | All | Not seen | Not seen |
| Europe503 people | 79% | 20% | 2% |
| South Asia489 people | 99% | 1% | Not seen |
Among the 2,504 people of the 1000 Genomes Project, in five world regions. These percentages describe groups of people, never anyone’s chance of having a trait.
Through time
How often the studied letter was read in ancient people, era by era, in the region chosen.
| Before farmingbefore 6500 BC | 46%26 of 56 copies read |
|---|---|
| First farmers6500 to 3000 BC | 13%114 of 868 copies read |
| Bronze Age3000 to 1200 BC | 14%100 of 728 copies read |
| Iron Age and Antiquity1200 BC to AD 600 | 12%124 of 1,018 copies read |
| Middle AgesAD 600 to 1500 | 7%36 of 552 copies read |
| Today1000 Genomes | 12%117 of 1,006 copies |
Neanderthal and Denisovan genomes
- Altai Neanderthal
- No copies
- Vindija Neanderthal
- No copies
- Chagyrskaya Neanderthal
- No copies
- Denisovan
- No copies
Neanderthals and Denisovans carried the other letter, so this letter is younger than our split with them.
The marker
- Gene or region
- IRF4
- Marker
- rs12203592
- Location
- Chromosome 6 · GRCh37 396,321 · GRCh38 396,321
- Letters studied
- C and T, with T as the studied allele
A DNA Traits report reads this marker in your raw DNA file and shows which of the three genotypes is yours, with how common it is. It counts the copies of the studied allele; it does not measure the trait itself.
- Marker
- IRF4 · rs12203592
- Location
- Chromosome 6 · GRCh37 396,321 · GRCh38 396,321
- Studied allele
- T
- Published statistic
- GCAT: beta -0.226 (SE 0.025) per T allele on the zero to three ease of suntan scale, P 8.22e-20, n 4,973 (Farre 2023 Supplementary Table S6); UK Biobank: OR 1.74 (1.69 to 1.76) per T for low tan response, P 1.05e-581, n 121,296, with replication meta-analysis P 4.40e-157 in 55,382 Europeans (Visconti 2018 Table 1); US nurses and health professionals: tanning ability beta -0.35 (SE 0.03) per T, P 3.3e-23 (Zhang 2013 Table 6) (Supplementary Table S6 (Ease suntan block, rs12203592 row) and Supplementary Table S1 (coding and sample size))
- 1000 Genomes Project phase 3, people with 0, 1 and 2 copies
- All regions 2332 / 160 / 12 · Africa 651 / 9 / 1 · The Americas 299 / 46 / 2 · East Asia 504 / 0 / 0 · Europe 395 / 99 / 9 · South Asia 483 / 6 / 0
What it cannot tell you
The same IRF4 marker as the freckling and hair greying cards, so these cards are not independent evidence.
Genome-wide association study in 176,678 Europeans reveals genetic loci for tanning response to sun exposure (Visconti et al., 2018)More in Skin & sun
- Ease of tanning association
- Severe sunburn history association
- Mole count association
- Facial pigmented spots association
- Ease of tanning (TYRP1)
- Ease of tanning (TRPS1)
- Ease of tanning (EMX2)
- Ease of tanning (SPIRE2)
- Ease of tanning (MC1R R151C)
- Tanning ability (ASIP region)
- Ease of sunburn (SLC45A2)
- Sunburn history (MC1R R160W)
- Stretch marks
See your own two letters.
Upload the raw DNA file you already have. Your report reads this marker and every other card studied for you, each with its evidence and its limits.