Characterization of Jk(a+^weak): a new blood group phenotype associated with an altered JK*01 allele

Abstract

A new phenotype with weakened Jk(a) expression on RBCs is associated with a JK*01-like allele, which may constitute a risk for hemolytic transfusion reactions if antigen-positive units are missed by routine serology.

Production of human monoclonal anti‐Jk3, recognising an epitope including the Jka/Jkb polymorphic site of the Kidd glycoprotein

“…These observations show that HIRO-294 is able to recognise the Jk a /Jk b polymorphic site located on the fourth extracellular loop of the Kidd glycoprotein. It has been described that the c.130G>A (p.Glu44Lys) mutation detected in the JK*01W.01 allele reduced the expression of the Kidd glycoprotein, corresponding to the Jk(a+ w ) phenotype (Wester et al, 2011). We also confirmed the weak reactivity of c.130A/A RBCs with HIRO-294 by flow cytometry.…”

“…During the hemagglutination titration study, we noticed that the reactivity of HIRO‐294 with the Jk(a+b−) cells was weaker than that of the Jk(a−b+) cells (Table ). A previous report indicated that the JK*01W.01 allele having the c.130G>A (p.Glu44Lys) mutation affected the expression of Kidd glycoprotein, accounting for the Jk(a+ w ) phenotype, and the allele was relatively common in Asian people (Wester et al, ). Therefore, we investigated the relationship between the c.130 genotype determined by multiplex PCR (Fig.…”

“…It has been described that the c.130G>A (p.Glu44Lys) mutation detected in the JK*01W.01 allele reduced the expression of the Kidd glycoprotein, corresponding to the Jk(a+ w ) phenotype (Wester et al , ). We also confirmed the weak reactivity of c.130A/A RBCs with HIRO‐294 by flow cytometry.…”

Changing practice: red blood cell typing by molecular methods for patients with sickle cell disease

“…Many discrepancies were associated with samples with single‐dose Fy b expression that were not originally detected as positive; 86% of Fy b discrepancies reacted weak+ to 2 + on the repeat serologic testing (http://onlinelibrary.wiley.com/doi/10.1111/trf.12987/suppinfo). Direct sequencing revealed one Jk a discrepancy explained by a JK*A nucleotide 130G>A change associated with weak antigen expression. Overall, discrepant results were equally associated with false‐positive (n = 34) and false‐negative (n = 33) historical serologic types.…”

A novel JK*02 allele in a French Canadian family

“…The molecular basis for the two main JK antigens is located at Nucleotide 838 (G for Jk a (Asp280), A for Jk b (Asn280)). Null alleles have been described in all populations, but are more frequent in Polynesian and Finn persons, and variant alleles are also described in black persons …”