title: The JR blood group system: identification of alleles that alter expression.
abstract: BACKGROUND
  The ABCG2 gene encodes antigens of the JR blood group system. Red blood cells (RBCs) from individuals homozygous for ABCG2 null alleles are nonreactive with polyclonal and monoclonal anti-Jr(a) . However, some RBCs have been defined as Jr(a+(W) /-) or Jr(a-), particularly when tested with polyclonal anti-Jr(a) . In an effort to resolve these apparent serologic ambiguities, the current study was undertaken.
  
  
  METHODS
  Hemagglutination of RBCs from two individuals known to express a single copy of functional ABCG2 were compared to RBCs from eight unrelated, previously characterized, Jr(a+(W) /-) donors. Standard polymerase chain reaction-based methods were used to characterize ABCG2 alleles.
  
  
  RESULTS
  Two monoclonal anti-Jr(a) clones agglutinated RBCs from the eight Jr(a+(W) /-) study subjects. Two of these subjects were homozygous for a missense ABCG2 change (c.1858A; Asp620Asn). Two were heterozygous for two missense changes; one was c.1858G>A and c.421C>A (Asp620Asn; Gln141Lys), and the other was c.1714A>C and c.421C>A (Ser572Arg; Gln141Lys). The remaining four subjects were heterozygous for c.421C>A (Gln141Lys), and for one of four null alleles.
  
  
  CONCLUSIONS
  We have identified three ABCG2 alleles that are newly associated with weakened Jr(a) expression. One of these is novel, the missense allele c.1714A>C (Ser572Arg) and two that have been previously described c.421C>A (rs2231142; Gln141Lys) and c.1858G>A (rs34783571; Asp620Asn). In addition, we found a novel, presumed null allele, c.1017_1019delCTC (Ser340del).
authors: Laboratory of Immunochemistry, New York Blood Center, New York, New York; Laboratory of Immunohematology and Genomics, New York Blood Center, Long Island City, New York; Rh Laboratory, Department of Pediatrics and Child Health, Faculty of Medicine, Department of Biochemistry and Medical Genetics, Faculty of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada; Japanese Red Cross Hokkaido Block Blood Center, Sapporo, Japan; Japanese Red Cross Kinki Block Blood Center, Ibaraki, Japan.
authors: Kim
authors: K
authors: Hue-Roye
authors: Teresa
authors: T
authors: Zelinski
authors: Adam
authors: A
authors: Cobaugh
authors: Christine
authors: C
authors: Lomas-Francis
authors: Toru
authors: T
authors: Miyazaki
authors: Yoshihiko
authors: Y
authors: Tani
authors: Connie M
authors: CM
authors: Westhoff
authors: Marion E
authors: ME
authors: Reid
mesh_terms: D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters / Q000235:genetics*; D000483:Alleles; D001789:Blood Group Antigens / Q000235:genetics*; D005260:Female; D006386:Hemagglutination Tests; D006579:Heterozygote; D006801:Humans; D008297:Male; D009363:Neoplasm Proteins / Q000235:genetics*
chemical_list: C116614:ABCG2 protein, human; D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters; D001789:Blood Group Antigens; D009363:Neoplasm Proteins