Fucosyltransferase 2 (FUT2) is a protein which regulates A/B/O blood groupings in certain Caucasian populations and is encoded for by the FUT2 gene.
A/B/O or Lewis blood groups are all produced from a common protein known as the H-antigen, with A and B groups processing this protein further an O groups leaving it unmodified. FUT2 is one of several enzymes involved in this processing and if lacking then H-antigen processing cannot occur and affected individuals will lack a classical A/B/O blood group 1.
One SNP in the FUT2 gene has been associated with this effect in certain populations, rs601338 or G12447A.
|rsID Number||Major Allele||Minor Allele||Minor Allele Frequency (%)||Major Amino Acid|
The risk ‘G’ allele of G12447A in the FUT2 gene has been associated with a lack of A/B/O blood type in individuals carrying two copies of the allele 2. Clinically such individuals will likely require highly specific donor blood if they require a transfusion however other effects have also been observed.
Those carrying two copies of the risk ‘G’ allele were found to be more susceptible to norovirus infection, the highly transmissible infection which causes severe gastroenteritis 3. It is unclear what if any steps individuals can take to mitigate this risk.
Discuss this information with your doctor before taking any course of action.