This gene encodes a protein that contains a mono-ADP-ribosylation (ART) motif. It is a member of the ADP-ribosyltransferase gene family but enzymatic activity has not been demonstrated experimentally. Antigens of the Dombrock blood group system are located on the gene product, which is glycosylphosphatidylinosotol-anchored to the erythrocyte membrane. Allelic variants, some of which lead to adverse transfusion reactions, are known.