Novel alleles at the Kell blood group locus that lead to Kell variant phenotype in the Dutch population. Issue 2 (25th August 2014)

• Record Type: Journal Article
• Authors: Ji, Yanli; Veldhuisen, Barbera; Ligthart, Peter; Haer‐Wigman, Lonneke; Jongerius, John; Boujnan, Mohamed; Ait Soussan, Aicha; Luo, Guangping; Fu, Yongshui; van der Schoot, C. Ellen; de Haas, Masja
• Is Part Of: Transfusion. Volume 55:Issue 2(2015)
• Page Start: 413
• Page End: 421
• Publication Date: 2014-08-25
• Subjects: Hematology -- Periodicals; Blood -- Transfusion -- Periodicals; Blood Group Antigens -- Periodicals; Blood Preservation -- Periodicals; Blood Transfusion -- Periodicals; 615
• DOI: 10.1111/trf.12838
• Languages: English
• ISSNs: 0041-1132

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="trf12838-sec-0001" sec-type="section"> <title>Background</title> <p>Alloantibodies directed against antigens of the Kell blood group system are clinically significant. In the Netherlands, the KEL1 antigen is determined in all blood donors. In this study, after phenotyping of KEL:1‐positive donors, genotyping analysis was conducted in KEL:1, –2 donors to identify possible <italic>KEL*02</italic> variant alleles.</p> </sec> <sec id="trf12838-sec-0002" sec-type="section"> <title>Study Design and Methods</title> <p>A total of 407 donors with the KEL:1, –2 phenotype were genotyped for the <italic>KEL*01/02</italic> polymorphism, followed by direct sequencing of the <italic>KEL</italic> gene if the <italic>KEL*02</italic> allele was detected. Two K<sub>0</sub> patients were also included. Transcript analysis was conducted in two probands with the <italic>KEL*02. M05</italic> allele defined by a synonymous mutation (G573G). Flow cytometry analysis to determine the expression of Kell antigen was performed.</p> </sec> <sec id="trf12838-sec-0003" sec-type="section"> <title>Results</title> <p>Thirty KEL:1, –2 individuals (30/407, 7.4%) with discrepant <italic>KEL*01/02</italic> genotype were identified. Seven novel alleles were identified: <italic>KEL*02(R86Q, R281W)mod, KEL*02(L133P)null, KEL*02(436delG)null, KEL*02(F418S)null, KEL*02(R492X)null, KEL*02(L611R)null, </italic> and <italic>KEL*02(R700X)null</italic>. Nine variant alleles described before were detected: <italic>KEL*02N.06</italic>, <italic>KEL*02N.15</italic>, <italic>KEL*02N.17</italic>, <italic>KEL*02N.19, KEL*02N.21, KEL*02M.02, KEL*02M.04, KEL*02M.05, </italic> and <italic>KEL*02(Q362K)mod</italic>. A transcript lacking Exon 16 was identified in two probands with the <italic>KEL*02M.05</italic> allele as described before. Finally, flow cytometry analysis showed a decreased total Kell expression and a relatively increased KEL1 expression in individuals with the KEL:1, 2null or KEL:1, 2mod phenotype, compared to KEL:1, 2 controls.</p> </sec> <sec id="trf12838-sec-0004" sec-type="section"> <title>Conclusion</title> <p>In 7.4% of a group of tested KEL:1, –2 Dutch donors, a <italic>KEL*02null</italic> or <italic>KEL*02mod</italic> allele was found. A relatively increased KEL1 antigen expression in KEL:1, 2null and KEL:1, 2mod individuals suggest that the expression of Kell‐XK complexes depends on the availability of the XK protein.</p> </sec> </abstract>