September 1991

A Variant Form of Thrombasthenia

Author Affiliations

From the Departments of Pediatrics (Drs Tarantino, Corrigan, and Jeter) and Pathology (Drs Glasser and Payne) and The Children's Research Center, The University of Arizona Health Sciences Center, Tucson. Dr Corrigan is now with Tulane University School of Medicine, New Orleans, La. Dr Tarantino is now with the University of Wisconsin Medical School, Madison.

Am J Dis Child. 1991;145(9):1053-1057. doi:10.1001/archpedi.1991.02160090105034

• 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 ≤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 Illa and lb 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.

(AJDC. 1991;145:1053-1057)