Sequencings

Markers / Gene

FUT2

2 positions in this gene are readable from a home DNA test.

Secretor status

rs601338 · chr19:49,206,674 · G/A · evidence: established

FUT2 decides whether you put blood-group sugars into saliva, gut lining and other secretions. About a fifth of Europeans have two broken copies and are non-secretors, which changes which gut bacteria settle in and which stomach bugs can get a grip.

If you carryWhat it means
No copiesSecretor
One copySecretor
Two copiesNon-secretor
Ancestry groupA (the effect version)
African49.1%
American34.1%
East Asian0.4%
European44.1%
South Asian28.3%

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.

Full detail on rs601338

Vitamin B12 levels

rs602662 · chr19:49,206,985 · G/A · evidence: strong

The same FUT2 gene behind secretor status also shows up as the strongest common genetic influence on measured vitamin B12 in blood, probably through its effect on which bacteria live in the gut and on H. pylori infection.

If you carryWhat it means
No copiesYou do not carry the higher-level version
One copyOne copy, so modestly higher B12 on a blood test
Two copiesTwo copies, so the highest average B12 on a blood test
Ancestry groupA (the effect version)
African49.2%
American35.2%
East Asian0.4%
European46.8%
South Asian28.3%

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.

Full detail on rs602662

Where this gene fits

If you have taken a home DNA test, these positions are already in your file.

Read my file