rs1042838
Neanderthal: the progesterone receptor
What this position does
About one European woman in three carries a progesterone receptor inherited from Neanderthals. In UK Biobank data, women carrying it had fewer bleedings in early pregnancy, fewer miscarriages and more children, which makes it one of the few archaic variants that looks clearly beneficial.
What each result means
| If you carry | What it means |
|---|---|
| No copies of the effect version CC | Not inherited Neither copy carries the Neanderthal receptor. |
| One copy AC | Inherited from one parent One copy. In the original analysis, carriers produced more progesterone receptor and had fewer early miscarriages. Roughly 29 per cent of European women are in this group. |
| Two copies AA | Inherited from both parents Two copies, which about 3 per cent of European women carry. |
Worth knowing. Everyone has this gene, whatever their sex. The fertility findings were measured in women.
How common each version is
| Ancestry group | A (the effect version) | |
|---|---|---|
| African | 0.6% | |
| American | 13.7% | |
| East Asian | 1.0% | |
| European | 17.9% | |
| South Asian | 6.6% |
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 | CC | AC | AA |
|---|---|---|---|
| African | 653 / 661 | 8 / 661 | 0 / 661 |
| European | 339 / 503 | 148 / 503 | 16 / 503 |
| East Asian | 494 / 504 | 10 / 504 | 0 / 504 |
| South Asian | 427 / 489 | 59 / 489 | 3 / 489 |
| American | 261 / 347 | 77 / 347 | 9 / 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: Archaic DNA.
Where this fits
Common questions
What is rs1042838?
rs1042838 is a position in the PGR gene on chromosome 11. About one European woman in three carries a progesterone receptor inherited from Neanderthals. In UK Biobank data, women carrying it had fewer bleedings in early pregnancy, fewer miscarriages and more children, which makes it one of the few archaic variants that looks clearly beneficial.
What does it mean if I have AA at rs1042838?
Inherited from both parents. Two copies, which about 3 per cent of European women carry.
What does it mean if I have CC at rs1042838?
Not inherited. Neither copy carries the Neanderthal receptor.
How do I find out my rs1042838 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: Archaic DNA.