A novel exonuclease (TaqMan) assay for rapid haptoglobin genotyping

作者:Renner Wilfried*; Jahrbacher Renate; Marx Neuhold Ernestine; Tischler Simone; Zulus Barbara
来源:Clinical Chemistry and Laboratory Medicine, 2016, 54(5): 781-783.
DOI:10.1515/cclm-2015-0586

摘要

Background: Haptoglobin is an acute-phase binding protein that scavenges free hemoglobin. The human haptoglobin gene (HP) is polymorphic with two main alleles, haptoglobin allele 1 (Hp1) and haptoglobin allele 2 (Hp2). The smaller Hp1 allele features no duplication and consists of four exons, whereas the larger Hp2 allele, containing a 1.7 kb duplication, consists of six exons, with the fifth and sixth being highly homologous to exons 3 and 4 of Hp1. Methods: We designed an exonuclease (TaqMan) assay targeting single nucleotide differences between the homologous regions of Hp1 and Hp2. The assay contained one probe specifically binding to a site in intron 4 of Hp2, and another probe binding equally to intron 4 of Hp1 and intron 6 of Hp2. Results: Measurement of post-PCR fluorescence allowed unambiguous discrimination of HP genotypes. Comparison with genotypes obtained by a method based upon allele-specific primers yielded fully corresponding results. Conclusions: The new HP genotyping method is fast, reliable, does not require real-time instruments and may be especially useful for high-throughput genotyping.