title: Identification and characterization of a novel P2Y 12 variant in a patient diagnosed with type 1 von Willebrand disease in the European MCMDM-1VWD study.
abstract: We investigated whether defects in the P2Y(12) ADP receptor gene (P2RY12) contribute to the bleeding tendency in 92 index cases enrolled in the European MCMDM-1VWD study. A heterozygous mutation, predicting a lysine to glutamate (K174E) substitution in P2Y(12), was identified in one case with mild type 1 von Willebrand disease (VWD) and a VWF defect. Platelets from the index case and relatives carrying the K174E defect changed shape in response to ADP, but showed reduced and reversible aggregation in response to 10 muM ADP, unlike the maximal, sustained aggregation observed in controls. The reduced response was associated with an approximate 50% reduction in binding of [(3)H]2MeS-ADP to P2Y(12), whereas binding to the P2Y(1) receptor was normal. A hemagglutinin-tagged K174E P2Y(12) variant showed surface expression in CHO cells, markedly reduced binding to [(3)H]2MeS-ADP, and minimal ADP-mediated inhibition of forskolin-induced adenylyl cyclase activity. Our results provide further evidence for locus heterogeneity in type 1 VWD.
authors.affiliation: Academic Unit of Haematology, School of Medicine and Biomedical Sciences, University of Sheffield, Sheffield, United Kingdom. m.daly@sheffield.ac.uk
authors.forename: Martina E
authors.initials: ME
authors.lastname: Daly
authors.forename: Ban B
authors.initials: BB
authors.lastname: Dawood
authors.forename: William A
authors.initials: WA
authors.lastname: Lester
authors.forename: Ian R
authors.initials: IR
authors.lastname: Peake
authors.forename: Francesco
authors.initials: F
authors.lastname: Rodeghiero
authors.forename: Anne C
authors.initials: AC
authors.lastname: Goodeve
authors.forename: Michael
authors.initials: M
authors.lastname: Makris
authors.forename: Jonathan T
authors.initials: JT
authors.lastname: Wilde
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Mumford
authors.forename: Stephen P
authors.initials: SP
authors.lastname: Watson
authors.forename: Stuart J
authors.initials: SJ
authors.lastname: Mundell
mesh_terms: D000244:Adenosine Diphosphate / Q000378:metabolism; D000818:Animals; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D005060:Europe; D006470:Hemorrhage / Q000150:complications / Q000235:genetics / Q000378:metabolism; D006801:Humans; D009154:Mutation / Q000235:genetics; D015539:Platelet Activation / Q000187:drug effects; D011485:Protein Binding; D058910:Purinergic P2 Receptor Agonists; D018048:Receptors, Purinergic P2 / Q000235:genetics* / Q000378:metabolism*; D058925:Receptors, Purinergic P2Y12; D012955:Societies, Medical; D014842:von Willebrand Diseases / Q000150:complications / Q000175:diagnosis* / Q000235:genetics / Q000378:metabolism*
chemical_list: C548576:P2RY12 protein, human; D058910:Purinergic P2 Receptor Agonists; D018048:Receptors, Purinergic P2; D058925:Receptors, Purinergic P2Y12; D000244:Adenosine Diphosphate