Antigens of the Diego blood group

Number of antigens 21: Dia, Dib, and Wra are among the most significant
Antigen specificity Protein
Amino acid sequence determines the specificity of Diego antigens
Antigen-carrying molecules Glycoprotein that transports anions
The Diego protein is a transmembrane, multi-pass protein that is integral to the RBC membrane. It is an anion antiporter that exchanges Cl- and HCO3- across the RBC membrane.
Molecular basis The SLC4A1 gene encodes the Diego antigens.
Located on chromosome 17 (17q21-22), the SLC4A1 gene contains 20 exons that span more than 18 kbp of DNA. The alleles Dib and Dia result from a SNP (2561C→T), and the corresponding Dib and Dia antigens differ by a single amino acid (P854L).
Frequency of Diego antigens Dia is found mainly in populations of Mongolian descent.
It is found in 36% of South American Indians, 12% of Japanese, and 12% of Chinese, whereas it is rare in Caucasians and Blacks (0.01%).
Dib is found universally in most populations (1).
Frequency of Diego phenotypes Di(a-b+) is found in >99.9% of Caucasians and Blacks and >90% of Asians.
Di(a+b+) found in <0.1% of Caucasians and Blacks and in 10% Asians.
Di(a+b-) found in <0.01% Caucasians, Blacks, and Asians.
Di(a-b-) found in 1 case only (1).

From: Chapter 11, The Diego blood group

Cover of Blood Groups and Red Cell Antigens
Blood Groups and Red Cell Antigens [Internet].
Dean L.
Bethesda (MD): National Center for Biotechnology Information (US); 2005.

NCBI Bookshelf. A service of the National Library of Medicine, National Institutes of Health.