Evidence · Replicated

What the research found

In the cited research, the C allele at rs1260326 was associated with slightly more cups of coffee a day among coffee drinkers.

TT: Fewer cups
CT: Middle
CC: More cups

Slight effect

What the study found

In the study, each copy went with cups of coffee a day among coffee drinkers about 0.04 cups a day higher on average.

Coffee drinkers of European and African American ancestry, all discovery and replication cohorts combined · 129,417 people · Table 1, rs1260326 row, trans-ethnic meta-analysis columns (effect from the random-effects meta-analysis of all stage 1 and stage 2 studies, footnote c; n in the row's last column)

Evidence: Genome-wide meta-analysis with independent replication
Who was studied: European ancestry; UK Biobank with US replication

1000 Genomes Project

How common each genotype is

How common each genotype is in the 1000 Genomes Project, by region
Region	TTFewer cups	CTMiddle	CCMore cups
All regions2,504 people	11%	36%	53%
Africa661 people	1%	17%	82%
The Americas347 people	16%	41%	43%
East Asia504 people	24%	49%	27%
Europe503 people	16%	51%	34%
South Asia489 people	5%	31%	65%

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.

Ancient genomes

Through time

How often the studied letter was read in ancient people, era by era, in the region chosen.

Region

Through time: Europe
Before farmingbefore 6500 BC	90%43 of 48 copies read
First farmers6500 to 3000 BC	60%428 of 715 copies read
Bronze Age3000 to 1200 BC	67%389 of 579 copies read
Iron Age and Antiquity1200 BC to AD 600	60%539 of 900 copies read
Middle AgesAD 600 to 1500	61%246 of 403 copies read
Today1000 Genomes	59%593 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.

For most ancient people only one of their two copies can be read, so these counts are copies read, not people. Close relatives, repeated samples and samples the archive marks as unreliable are left out. Damage in old DNA can fake this letter, so it is counted only from samples treated to remove that damage and from high-quality genomes. Ancient genomes from the Allen Ancient DNA Resource (AADR v66): 15,136 people.

rs1260326

The marker

Gene or region: GCKR
Marker: rs1260326
Location: Chromosome 2 · GRCh37 27,730,940 · GRCh38 27,508,073
Letters studied: C and T, with C 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: GCKR · rs1260326
Location: Chromosome 2 · GRCh37 27,730,940 · GRCh38 27,508,073
Studied allele: C
Published statistic: Per T, cups a day (Cornelis 2015 Table 1): stage 1 -0.04 (SE 0.01), P 1.06e-7 (EUR n <= 91,462); stage 2 European -0.03 (0.01), P 0.02 (n <= 30,062); all stages -0.04 (0.01), log10 Bayes factor 6.48, n 129,417; the card counts C, so each beta flips sign. Coffee +1.36% per C, joint P 2.62e-19 (Zhong 2019 Table 2). UK Biobank combined caffeine from coffee and tea: beta -0.02297 SD per T, P 4.2e-22 (Said 2020 Table S12) (Table 1, rs1260326 row, trans-ethnic meta-analysis columns (effect from the random-effects meta-analysis of all stage 1 and stage 2 studies, footnote c; n in the row's last column))
1000 Genomes Project phase 3, people with 0, 1 and 2 copies: All regions 282 / 905 / 1317 · Africa 7 / 110 / 544 · The Americas 54 / 143 / 150 · East Asia 119 / 247 / 138 · Europe 79 / 255 / 169 · South Asia 23 / 150 / 316

See this card in the sample report

Limits

What it cannot tell you

Intake was reported as cups a day by coffee drinkers. This marker is also read on the triglyceride card.

Genome-wide meta-analysis identifies six novel loci associated with habitual coffee consumption (Coffee and Caffeine Genetics Consortium, Cornelis et al., 2015)

The same topic

More in Nutrition & metabolism

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