A Caucasian JK*A/JK*B woman with Jk(a+b-) red blood cells, anti-Jkb, and a novel JK*B allele c.1038delG.
The Kidd blood group on the red blood cell (RBC) glycoprotein urea transporter-B has a growing number of weak and null alleles in its gene SLC14A1 that are emerging from more widespread genotyping of blood donors and patients. We investigated a 64-year-old Caucasian woman of Polish-Czech descent who developed anti-Jkb detected in solid-phase RBC adherence testing within 12 days after 7 units of RBCs were transfused. Her RBCs subsequently typed Jk(a+b–) by licensed reagents and human antisera. Nevertheless, in RBC genotyping (BioArray HEA BeadChip, Immucor, Warren, NJ) performed in our transfusion service on all patients with alloantibodies, her Kidd typing was JK*A/JK*B based on the Jka/Jkb single nucleotide polymorphism in exon 9 (c.838G>A, p.Asp280Asn). Genomic analysis and cDNA sequencing of her JK*B allele revealed a novel single-nucleotide deletion of c.1038G in exon 11, predicting a frameshift and premature stop (p.Thr346Thrfs*5) after translation of nearly 90 percent of the expressed exons 4–11. This allele has been provisionally named JK*02N.14, subject to approval by the International Society of Blood Transfusion Working Party. The site of this variant is closer to the C-terminus than that of any allele associated with the Jk(a–b–) phenotype reported to date. Routine genotyping of patients with RBC alloantibodies can reveal variants posing potential risk of alloimmunization. Continuing investigation of Kidd variants may shed light on the structure of Kidd antigens and the function of urea transporter-B.
Professor of Pathology, Feinberg School of Medicine, Northwestern University, and Medical Director, Blood Bank, Northwestern Memorial Hospital, Feinberg 7-301, 251 E. Huron St., Chicago, IL 60611.
Glenn
G
Ramsey
Manager, Blood Bank, Northwestern Memorial Hospital.
Ricardo D
RD
Sumugod
Associate Professor of Pathology, Feinberg School of Medicine, Northwestern University, and Medical Co-Director, Blood Bank, Northwestern Memorial Hospital.
Paul F
PF
Lindholm
Senior Medical Technologist, Blood Bank, Northwestern Memorial Hospital.
Jules G
JG
Zinni
Supervisor.
Jessica A
JA
Keller
Manager.
Trina
T
Horn
Director, National Molecular Laboratory, American Red Cross, Philadelphia, PA.
Margaret A
MA
Keller
D000483:Alleles; D000918:Antibody Specificity; D001787:Blood Group Incompatibility / Q000097:blood; D001788:Blood Grouping and Crossmatching; D018389:Codon, Nonsense / Q000235:genetics; D005260:Female; D016368:Frameshift Mutation; D006801:Humans; D007518:Isoantibodies / Q000096:biosynthesis / Q000097:blood* / Q000276:immunology; D007667:Kidd Blood-Group System / Q000235:genetics*; D026901:Membrane Transport Proteins / Q000737:chemistry / Q000235:genetics* / Q000276:immunology; D008875:Middle Aged; D008958:Models, Molecular; D020411:Oligonucleotide Array Sequence Analysis; D010641:Phenotype; D017354:Point Mutation; D020641:Polymorphism, Single Nucleotide; D019106:Postoperative Hemorrhage / Q000628:therapy; D011487:Protein Conformation; D017422:Sequence Analysis, DNA; D017384:Sequence Deletion; D065227:Transfusion Reaction; D000096982:Urea Transporters
D018389:Codon, Nonsense; D007518:Isoantibodies; D007667:Kidd Blood-Group System; D026901:Membrane Transport Proteins; D000096982:Urea Transporters