GENOMIC TYPING OF THE KIDD BLOOD-GROUP LOCUS BY A SINGLE-TUBE ALLELE-SPECIFIC PRIMER PCR TECHNIQUE

The Kidd (JK) blood group system is clinically important in transfusio n medicine, Alloantibodies to antigens in this system may be produced following blood transfusion or during pregnancy and can result in seri ous haemolytic transfusion reactions and haemolytic disease of the new born (HDN), JK antigens on erythrocytes are carried by glycoproteins w ith the capacity to transport urea through cell membranes, cDNA comple mentary to mRNA transcribed at the JK locus was cloned in 1994. The mo lecular basis of the Jk(a)/Jk(b) blood group polymorphism was recently shown to be a single nucleotide substitution predicting an amino acid change (Asp280Asn) in an extracellular loop of the JK glycoprotein, A fter confirmation of the JK gene polymorphism we developed a rapid and robust technique for JK genotyping with allele-specific primers in a single-tube PCR. In addition, a 217 bp intron located at nucleotides 8 11-812 in the JK gene was found and sequenced, The genotyping test was validated with samples from 106 Caucasian Swedish and 13 Black South African random blood donors, Complete phenotype-genotype correlations were obtained, However, four Jk(a-b-) samples of Polynesian and Finnis h origin typed as Jk(b)Jk(b). Potential use of the presented method ca n be predicted in clinical transfusion medicine including prenatal det ermination of the JK genotype in a fetus at risk for HDN caused by JK antibodies.