A pair of blood group antigens independent of the ABO locus. The alleles are codominant and both can be expressed in an individual, so there are three phenotypes: MM, NN, and MN. Glycophorin has M or N activity depending upon carbohydrate epitopes attached to the N-terminal region. The MN phenotype has been associated with essential hypertension.
http://www.ncbi.nlm.nih.gov/projects/gv/mhc/xslcgi.cgi?cmd=bgmut/home The Blood Group Antigen Gene Mutation database.
Subjects: Medicine and Health.