obsolete blood group, duffy system (obsolete MONDO:0044219)
OBSOLETE. The Duffy blood group system, which consists of 4 alleles, 5 phenotypes, and 5 antigens, is important in clinical medicine because of transfusion incompatibilities and hemolytic disease of the newborn. Duffy antigens are located on ACKR1 (OMIM:613665), or DARC, an acidic glycoprotein found on erythrocytes and other cells throughout the body. The 2 principal antigens, Fy(a) and Fy(b), are produced by the FYA and FYB codominant alleles (see {613665.0001}). Four phenotypes are defined by the corresponding antibodies, anti-Fy(a) and anti-Fy(b): Fy(a+b-), Fy(a-b+), Fy(a+b+), and Fy(a-b-). Fy(a-b-), or Duffy null, is the major phenotype in African and American blacks and is characterized by the presence of Fy(b) on nonerythroid cells, but an absence of Fy(b) on erythrocytes. The Fy(a-b-) phenotype is associated with complete resistance to infection by the malarial parasite Plasmodium vivax (see OMIM:611162). Individuals with the Fy(a-b-) phenotype have the FYB-erythroid silent (FYB-ES) allele with a mutation in the DARC promoter ({613665.0002}). A fifth phenotype, Fy(bwk), or Fy(x), is characterized by weak Fy(b) expression on erythrocytes due to a reduced amount of protein. Individuals with the Fy(bwk) phenotype have the FYB-weak (FYB-WK) allele, also called the FYX allele, with a missense mutation in DARC ({613665.0003}). Other Duffy antigens include Fy3, Fy4, Fy5, and Fy6 (reviews by {21:Pogo and Chaudhuri (2000)}, {10:Langhi and Bordin (2006)}, and {14:Meny (2010)}).
FY
related
blood group, Duffy system
exact