Two previously proposed P-1/P-2-differentiating and nine novel polymorphisms at the A4GALT (P-k) locus do not correlate with the presence of the P1 blood group antigen
Background: The molecular genetics of the P blood group system and the absence of P1 antigen in the p phenotype are still enigmatic. One theory proposes that the same gene encodes for both the P1 and P-k glycosyltransferases, but no polymorphisms in the coding region of the P-k gene explain the P-1/P-2 phenotypes. We investigated the potential regulatory regions up- and downstream of the A4GALT (P