rs3798220
Lipoprotein(a), the cholesterol nobody measures
What this position does
Lp(a) is a cholesterol-carrying particle whose level is set almost entirely by genetics and barely moves with diet, exercise or statins. High Lp(a) is a genuinely independent risk factor for heart disease, and it is not on a standard cholesterol panel unless you ask.
What each result means
| If you carry | What it means |
|---|---|
| No copies of the effect version TT | You do not carry it, though other variants can still raise Lp(a) Neither copy carries this raised-Lp(a) version. Other variants can still raise it, so this is not a clear result. |
| One copy CT | One copy, and asking for an Lp(a) blood test is the clear next step Associated with substantially higher Lp(a) and a raised cardiovascular risk. This is one of the few results here with a clear next step: ask for an Lp(a) blood test, which most people are never offered. |
| Two copies CC | Two copies, and an Lp(a) blood test is the clear next step Uncommon, and associated with markedly higher Lp(a). An Lp(a) measurement is the right next step. |
Worth knowing. Lp(a) is measured directly with a cheap blood test, and the measurement is what counts. This variant is a reason to ask for it.
How common each version is
| Ancestry group | C (the effect version) | |
|---|---|---|
| African | 0.5% | |
| American | 21.6% | |
| East Asian | 8.8% | |
| European | 1.0% | |
| South Asian | 0.2% |
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 | 655 / 661 | 6 / 661 | 0 / 661 |
| European | 493 / 503 | 10 / 503 | 0 / 503 |
| East Asian | 415 / 504 | 89 / 504 | 0 / 504 |
| South Asian | 487 / 489 | 2 / 489 | 0 / 489 |
| American | 219 / 347 | 106 / 347 | 22 / 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 rs3798220?
rs3798220 is a position in the LPA gene on chromosome 6. Lp(a) is a cholesterol-carrying particle whose level is set almost entirely by genetics and barely moves with diet, exercise or statins. High Lp(a) is a genuinely independent risk factor for heart disease, and it is not on a standard cholesterol panel unless you ask.
What does it mean if I have CC at rs3798220?
Two copies, and an Lp(a) blood test is the clear next step. Uncommon, and associated with markedly higher Lp(a). An Lp(a) measurement is the right next step.
What does it mean if I have TT at rs3798220?
You do not carry it, though other variants can still raise Lp(a). Neither copy carries this raised-Lp(a) version. Other variants can still raise it, so this is not a clear result.
How do I find out my rs3798220 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.