Diego antigen system

History
The Diego system was discovered in 1955 in one Mrs. Diego when her child was found to suffer from HDN. The child was type Dia. A second type Dib was discovered in 1967 but the other types only began to be discovered in 1995. ,

Definition
Blood is classified in the Diego system by the form of the band 3 protein, coded for by the gene SLC41A (Solute Carrier family 4, Anion exchanger, member 1). Each allele of the gene SLC41A is classified as a separate blood group. The band 3 protein functions in the transport of Cl- and carbonate.

The system
There are 21 known Diego blood types, the most common is Di(a-b+); found in over 99.9% of Caucasians and Blacks, and in about 90% of Asians. Most of the remaining 10% of Asians are (a+b+). The cultural distribution of the blood group lends it some importance to the science of anthropology.