rs4977574
The 9p21 heart disease locus
What this position does
The first common variant ever linked to coronary artery disease, and still one of the strongest. Remarkably, it acts independently of cholesterol, blood pressure, diabetes and smoking, which is why it was missed for so long.
What each result means
| If you carry | What it means |
|---|---|
| No copies of the effect version AA | You have the lower-risk version on both copies Two copies of the lower-risk version. |
| One copy AG | One higher-risk copy, roughly 1.25 times the background risk Roughly 1.25 times the background risk of coronary artery disease. |
| Two copies GG | Two higher-risk copies, roughly 1.5 times the background risk Roughly 1.5 times the background risk. Carried by about a quarter of Europeans. The response is the ordinary one: know your blood pressure and cholesterol, and do not smoke. |
How common each version is
| Ancestry group | G (the effect version) | |
|---|---|---|
| African | 14.1% | |
| American | 41.6% | |
| East Asian | 53.1% | |
| European | 49.2% | |
| South Asian | 48.4% |
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 | AA | AG | GG |
|---|---|---|---|
| African | 491 / 661 | 154 / 661 | 16 / 661 |
| European | 133 / 503 | 245 / 503 | 125 / 503 |
| East Asian | 113 / 504 | 247 / 504 | 144 / 504 |
| South Asian | 137 / 489 | 231 / 489 | 121 / 489 |
| American | 113 / 347 | 179 / 347 | 55 / 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: Health-adjacent.
Where this fits
Common questions
What is rs4977574?
rs4977574 is a position in the CDKN2B-AS1 gene on chromosome 9. The first common variant ever linked to coronary artery disease, and still one of the strongest. Remarkably, it acts independently of cholesterol, blood pressure, diabetes and smoking, which is why it was missed for so long.
What does it mean if I have GG at rs4977574?
Two higher-risk copies, roughly 1.5 times the background risk. Roughly 1.5 times the background risk. Carried by about a quarter of Europeans. The response is the ordinary one: know your blood pressure and cholesterol, and do not smoke.
What does it mean if I have AA at rs4977574?
You have the lower-risk version on both copies. Two copies of the lower-risk version.
How do I find out my rs4977574 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: Health-adjacent.