Rs1047781

rs1047781, also known as Ile129Phe, is found on chromosome 19 in the alpha(1,2)-fucosyltransferase FUT2 gene. The wild-type rs1047781(A) encodes the 'Secretor' allele, while rs1047781(T) encodes the 'nonsecretor' (se2 or sej) allele.

This basis for FUT2 nonsecretor status is found primarily in Japanese. In Caucasians, nonsecretor status is associated with the se1 allele of rs601338, and rs1047781 genotype shows almost no variation. In Japanese, the se1 allele is absent, but 15% of individuals are non-secretors based on being homozygous for rs1047781(T;T).