Schematic representation of the RhD proteins observed in the 5 DAU phenotypes.

All DAU types share a T379M substitution (black disk) that is located in the twelfth transmembrane protein segment. DAU-1 to DAU-4 have additional substitutions: the S230I substitution of DAU-1 and the E233Q substitution of DAU-4 are both located in exofacial loop 4; the R70Q and S333N substitutions of DAU-2 position near the border of intramembrane and intracellular protein segments; the V279M substitution of DAU-3 locates at an intramembraneous protein segment proximate to exofacial loop 5.