title: A variant form of thrombasthenia.
abstract: We encountered two siblings with abnormal bruising since infancy. Studies revealed functional platelet defects characterized by a lack of platelet aggregation and adenosine triphosphate release on exposure to adenosine diphosphate and collagen as well as variable responses with ristocetin (at concentrations of less than or equal to 1.25 g/L) and arachidonic acid. In addition, little or no platelet aggregation was observed after exposure to hexadimethrine bromide (Polybrene), the calcium ionophore A23187, and the thromboxane/endoperoxide analogue U46619. The membrane proteins IIIa and Ib were present, as determined with monoclonal antibody testing, and no platelet-associated IgG was found. Platelet analysis with routine electron microscopy and ultrastructural cytochemistry revealed normal morphologic features and no deficiencies in the number of alpha granules dense bodies and other organelles. The platelet abnormality may represent a new variant of thrombasthenia.
authors.affiliation: Department of Pediatrics, University of Arizona Health Sciences Center, Tucson.
authors.forename: M D
authors.initials: MD
authors.lastname: Tarantino
authors.forename: J J
authors.initials: JJ
authors.lastname: Corrigan
authors.forename: L
authors.initials: L
authors.lastname: Glasser
authors.forename: C M
authors.initials: CM
authors.lastname: Payne
authors.forename: M A
authors.initials: MA
authors.lastname: Jeter
mesh_terms: D000244:Adenosine Diphosphate / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000378:metabolism; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000494:pharmacology; D001792:Blood Platelets / Q000648:ultrastructure; D002648:Child; D002675:Child, Preschool; D003094:Collagen / Q000494:pharmacology; D005260:Female; D006801:Humans; D008297:Male; D008854:Microscopy, Electron; D010974:Platelet Aggregation / Q000187:drug effects; D010980:Platelet Membrane Glycoproteins / Q000032:analysis; D012310:Ristocetin / Q000494:pharmacology; D013915:Thrombasthenia / Q000097:blood / Q000235:genetics*
chemical_list: D001095:Arachidonic Acids; D010980:Platelet Membrane Glycoproteins; D012310:Ristocetin; D016718:Arachidonic Acid; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D003094:Collagen