A structure-based analysis of the Kell blood group system.

Kell is one of the most complex blood group systems, with a highly polymorphic genetic background. Extensive allelic variations in the gene affect the encoded erythrocyte surface protein Kell. Genetic variants causing aberrant splicing, premature termination of protein translation, or specific amino acid exchanges lead to a variety of different phenotypes with altered Kell expression levels or changes in the antigenic properties of the Kell protein.