Single point mutation in human glycoprotein IIIa is associated with a new platelet-specific alloantigen (Mo) involved in neonatal alloimmune thrombocytopenia

Abstract

Here we describe a new platelet-specific alloantigen that was identified in a case of neonatal alloimmune thrombocytopenia. This antigen has provisionally been called “Mo.” By studying the Mo family, it was shown to be inherited in an autosomal dominant manner. Immunoprecipitation and Western blot analysis showed that the antigen resides on platelet glycoprotein IIIa (GP IIIa). Genomic analysis, performed by applying polymerase chain reaction and sequencing, showed a C-->G substitution of base pair 1267 of the coding region of the DNA for GP IIIa, resulting in a substitution of Proline407 by Alanine407. That this substitution is associated with the antigen could be demonstrated by restriction fragment length polymorphism analysis of cDNA, prepared from platelet RNA, and of genomic DNA. It was confirmed by dot-blot hybridization with allele-specific oligonucleotides. All family members, also those being Mo antigen-positive, were healthy. None of them appeared to suffer from increased tendency of bleeding or thrombosis. Thus, the Mo mutation does not lead to significant platelet dysfunction in vivo with heterozygous carriers. One of 450 random healthy blood donors who were tested was positive for the Mo antigen. Typing was performed by the classical serologic methods as well as by DNA analysis.

Human platelet alloantigens (HPAs): PCR‐SSP genotyping of a UK population for 15 HPA alleles

“…The Gov PCR-SSP primer pairs described in Schuh et al (2002) can be used under the same PCR conditions described in this report and we recommend their inclusion for comprehensive HPA genotyping. unless otherwise stated (n = 200) German (Kiefel et al1993) unless otherwise stated Austrian (Holensteiner et al 1995) (n = 900) Finnish (Kekomaki et al 1995) (n = 200, unless otherwise stated) GP1A*1 (HPA-5a) 0.914 0.903 (n = 339) 0.902 0.889 (n = 572) 0.892 0.95 GP1A*2 (HPA-5b) 0.086 0.097 (n = 339) 0.098 0.111 (n = 572) 0.108 0.05 GP1BA*1 (HPA-2a) 0.925 0.902 0.934 0.940 (n = 474) 0.918 0.91 GP1BA*2 (HPA-2b) 0.075 0.098 0.066 0.060 (n = 474) 0.082 0.09 GP2B*1 (HPA-3a) 0.627 0.607 0.555 0.616 (n = 568) 0.612 0.59 GP2B*2 (HPA-3b) 0.373 0.393 0.445 0.384 (n = 568) 0.388 0.41 GP2B*3 (HPA-9bw) 0.000 NT 0.003 (n = 500) NT NT NT (Noris et al 1995) GP3A*1 0.840 0.825 0.846 0.834 (n = 473) 0.852 0.86 (HPA-1a/-4a/-6a) GP3A*2 (HPA-1b) 0.161 0.175 0.154 0.166 (n = 473) 0.148 0.14 GP3A*3 (HPA-4b) 0.000 0.000 0.000 0.000 (n = 964) NT NT GP3A*4 (HPA-6b) 0.000 0.000 (n = 166) NT NT NT 0.01 (n = 127) GP3A*5 (HPA-7bw) 0.000 NT 0.001 (n = 450) (Kuijpers et al 1993) NT NT NT GP3A*6 (HPA-8bw) 0.000 NT NT 0.000 (n = 300) (Kroll et al 1990) NT NT GP3A*7 (HPA-10bw) 0.000 NT NT NT NT NT GP3A*8 (HPA-11bw) 0.000 NT 0.000 (n = 400) (Simsek et al 1994) NT NT NT NT, not tested.…”

Eleven human platelet systems studied in the Vietnamese and Ma'ohis Polynesian populations

“…BstNI for HPA-6w (15), HPA-9w (16), Gov (17), and the deletion associated with HPA-3b (18); Mnl1 for HPA-5 (14); Bsp1286 I for HPA-7w (19); Ava I for HPA-10w (20); and Mae III for HPA-11w (21). The w 2 test was used to test Hardy-Weinberg equilibrium.…”

The Arg633His substitution responsible for the private platelet antigen Groa unravelled by SSCP analysis and direct sequencing

“…The GP IIIa (b 3 ) subunit of the glycoprotein (GP) IIb/IIIa complex (Ginsberg et al, 1988;Phillips et al, 1991) (also known as the integrin a IIb b 3 ) (Hynes, 1987), which functions as a fibrinogen receptor on platelets, carries the majority of these alloantigen determinants, i.e. those belonging to the HPA-1, -4, -6W, -7W, -8W systems (van der Schoot et al, 1986;Rosa & McEver, 1989;McFarland et al, 1993;Kuijpers et al, 1993;Kroll et al, 1990). The recently described private platelet antigen Gro a also resides on GP IIIa (Simsek et al, 1994b).…”

“…The basis for all known HPA systems lies in single point mutations, leading to a single amino acid substitution (Kuijpers et al, 1992(Kuijpers et al, , 1993Newman et al, 1989;Lyman et al, 1990;Wang et al, 1991Wang et al, , 1993Simsek et al, 1994a;Santoso et al, 1994;Noris et al, 1995).…”