title: The Montreal platelet syndrome kindred has type 2B von Willebrand disease with the VWF V1316M mutation.
abstract: Montreal platelet syndrome (MPS), hitherto described in only one kindred, is a hereditary thrombocytopenia associated with mucocutaneous bleeding, giant platelets, and spontaneous platelet aggregation in vitro. These are features shared with some forms of type 2B von Willebrand disease (VWD); however, the MPS kindred had not been investigated for VWD. We found that all affected MPS family members had borderline to normal von Willebrand factor antigen (VWF:Ag; 0.43-0.75 U/mL), discrepantly low ristocetin cofactor activity (VWF:RCo; 0.16-0.29 U/mL), and normal factor VIII coagulant activity (FVIII:C; 0.57-1.04 U/mL). Unaffected family members all had normal VWF:Ag, VWF:RCo, and FVIII:C levels. In addition, persons with MPS, but not unaffected family members, had loss of plasma (but not platelet) high molecular weight VWF multimers, and were heterozygous for the previously reported V1316M type 2B VWD mutation. Thus, in reevaluating this kindred, we determined that patients with MPS have type 2B VWD with the V1316M VWF mutation.
authors.affiliation: Division of Hematology and Hematologic Malignancies, Department of Medicine, University of Calgary, Calgary, AB, Canada.
authors.forename: Shannon C
authors.initials: SC
authors.lastname: Jackson
authors.forename: Gary D
authors.initials: GD
authors.lastname: Sinclair
authors.forename: Stephanie
authors.initials: S
authors.lastname: Cloutier
authors.forename: Zhaoxia
authors.initials: Z
authors.lastname: Duan
authors.forename: Margaret L
authors.initials: ML
authors.lastname: Rand
authors.forename: Man-Chiu
authors.initials: MC
authors.lastname: Poon
mesh_terms: D019943:Amino Acid Substitution / Q000235:genetics; D001780:Blood Coagulation Tests; D001791:Blood Platelet Disorders / Q000150:complications* / Q000235:genetics*; D001792:Blood Platelets / Q000473:pathology; D004252:DNA Mutational Analysis; D005190:Family; D005260:Female; D006801:Humans; D008297:Male; D008715:Methionine / Q000235:genetics; D020125:Mutation, Missense / Q000502:physiology; D010375:Pedigree; D010974:Platelet Aggregation / Q000235:genetics; D013577:Syndrome; D014633:Valine / Q000235:genetics; D014842:von Willebrand Diseases / Q000150:complications* / Q000235:genetics / Q000473:pathology; D014841:von Willebrand Factor / Q000235:genetics*
chemical_list: D014841:von Willebrand Factor; D008715:Methionine; D014633:Valine