DNA Traits · Sleep & rhythms
Daytime sleepiness association
How often people doze off during the day without meaning to.
What the research found
In the cited research, the T allele at rs1846644 was associated with less frequent unintended daytime dozing in the studied cohorts.
- CC
- More often
- CT
- Middle
- TT
- Less often
What the study found
In the study, each copy went with how often people doze off in the daytime without meaning to, on a four-step scale from never to all of the time about 0.01 points lower on average.
- Evidence
- Genome-wide association with nominal support in independent cohorts
- Who was studied
- European-ancestry UK Biobank participants; nominal support in Scandinavian cohorts using related sleepiness questions
How common each genotype is
| Region | CCMore often | CTMiddle | TTLess often |
|---|---|---|---|
| All regions2,504 people | 13% | 41% | 45% |
| Africa661 people | 4% | 25% | 72% |
| The Americas347 people | 14% | 46% | 40% |
| East Asia504 people | 6% | 39% | 55% |
| Europe503 people | 17% | 53% | 30% |
| South Asia489 people | 31% | 50% | 19% |
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 | 93%38 of 41 copies read |
|---|---|
| First farmers6500 to 3000 BC | 61%307 of 504 copies read |
| Bronze Age3000 to 1200 BC | 56%236 of 425 copies read |
| Iron Age and Antiquity1200 BC to AD 600 | 55%320 of 579 copies read |
| Middle AgesAD 600 to 1500 | 64%286 of 445 copies read |
| Today1000 Genomes | 56%566 of 1,006 copies |
Neanderthal and Denisovan genomes
- Altai Neanderthal
- 2 copies
- Vindija Neanderthal
- 2 copies
- Chagyrskaya Neanderthal
- 2 copies
- Denisovan
- 2 copies
Neanderthals and Denisovans carried this letter too: it is the older of the two.
The marker
- Gene or region
- KSR2
- Marker
- rs1846644
- Location
- Chromosome 12 · GRCh37 117,938,380 · GRCh38 117,500,575
- 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
- KSR2 · rs1846644
- Location
- Chromosome 12 · GRCh37 117,938,380 · GRCh38 117,500,575
- Studied allele
- T
- Published statistic
- beta -0.011 per T (SE 0.001), P 2.5e-27, T frequency 0.59, n 452,071 (BOLT-LMM, Supplementary Table 3); the unrelated PLINK subset prints 0.011 (SE 0.001), P 2.52e-18, n 337,539 without naming the allele (Supplementary Data 1); HUNT -0.013 per T (SE 0.005), P 0.012, n 29,906; Health 2000 Epworth -0.123 per T (SE 0.067), P 0.069, n 4,546; Fisher P 0.007 (Supplementary Table 11) (Supplementary Information, Supplementary Table 3 (BOLT-LMM, without BMI adjustment; alleles E/A T/C); Abstract and Methods (n 452,071; answers coded 1 to 4))
- 1000 Genomes Project phase 3, people with 0, 1 and 2 copies
- All regions 337 / 1031 / 1136 · Africa 25 / 163 / 473 · The Americas 47 / 161 / 139 · East Asia 28 / 197 / 279 · Europe 87 / 266 / 150 · South Asia 150 / 244 / 95
What it cannot tell you
The association is with self-reported daytime sleepiness, not general fatigue, alertness measured today or a need for more sleep. Independent evidence for this individual marker was nominal; replication of the combined 42-marker score is not validation of a personal single-marker prediction. It is not a test for narcolepsy, sleep apnea or another sleep disorder. Only the studied C/T allele pair is interpreted.
Genome-wide association analysis of self-reported daytime sleepiness identifies 42 loci that suggest biological subtypes (Wang et al., 2019)More in Sleep & rhythms
- Morning preference association
- Snoring tendency association
- Sleep efficiency association
- Overnight sleep episodes association
- Sleep midpoint timing association
- Daytime napping association
- Difficulty sleeping association
- Morning preference (RGS16)
- Morning preference (AK5)
- Snoring (POC5)
- Snoring (TRAM1)
- Daytime napping (TLE4)
- Daytime napping (STK32A)
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.