HPA‐5 typing discrepancy reveals an Ile503Leu substitution in platelet GPIa (α₂ integrin)

Abstract

Feto-maternal alloimmunization was ruled out: the neonatal thrombocytopenia probably resulted from maternal anti-GPIIbIIIa autoantibodies. This case highlights that platelet typing should be performed using two different methods to avoid false diagnosis.

Comparison of a Simple-Probe Real-Time PCR and Multiplex PCR Techniques for HPA-1 to HPA-6 and HPA-15 Genotyping

“…Regarding HPA-5 discrepant results (n = 2), GPIa exon 13 se-quencing confirmed the HPA-5a5b genotype and revealed 1594A>C polymorphism (rs199808499) in both samples. This mutation near the HPA-5 polymorphism (5 side) could lead to an Ile503Leu amino acid change as previously described (17). Additionally, in five samples of HPA-6 discrepant results, a 1545G>A polymorphism (rs4634) adjacent to the 1544G>A SNP was demonstrated in all samples.…”

“…Factors involved in selecting HPA genotyping techniques include throughput, cost, time consumption, equipment, and personnel. In addition, consideration of primer and probe design using in‐house and commercial kits is needed, especially in genotype discrepancy results of HPA‐1 , HPA‐5 , HPA‐6 , and HPA‐15 . Therefore, two genotyping techniques using different primer sets should be employed routinely by laboratories to avoid misinterpretation.…”

“…Nevertheless, the real-time PCR technique has a limitation for HPA-6 genotyping because of a 1545 G>A polymorphism (rs4634) adjacent to the 1544G>A SNP, as previously described (11). Moreover, an additional limitation for HPA-5 genotyping by BeadChip Technology (BioArray, Immucor, Paris, France) due to a 1594A>C SNP (rs199808499) near the 1600 G>A SNP was recently reported (17). The purposes of this study are to compare the results of HPA-1 to HPA-6 and HPA-15 genotyping obtained by a simple-probe realtime PCR technique with the multiplex PCR technique and to determine whether a simple-probe real-time PCR can be used to screen platelet donors.…”