The Augustine blood group system, 48 years in the making

The high-prevalence antigen, Ata, was first identified in 1967, but it was not until 2015 that Ata became AUG1 of a new blood group system, Augustine (AUG). The new system was established after the identification of the gene encoding Ata and the recognition of a null phenotype (AUG:–1,–2) in an At(a–) patient with an antibody (anti-AUG2) reactive with At(a–) red blood cells. The At(a–) phenotype is very rare and, with the exception of the one family with the null phenotype, has only been found in individuals of African origin. Anti-Ata has been implicated in immediate and delayed hemolytic transfusion reactions, but not in severe hemolytic disease of the fetus and newborn. The Augustine gene is SLC29A1, which encodes the equilibrative nucleoside transporter ENT1. At(a–) (AUG:–1,2) results from homozygosity for c.1171G>A, encoding Glu391Lys, whereas the AUGnull (AUG:–1,–2) phenotype results from homozygosity for a splice site mutation, c.589+1G>C, in the only family where it has been found. Absence of ENT1 in that family may be associated with pseudogout and abnormal bone calcification.