Clinical and laboratorial characterization of a cohort of patients with hereditary platelet disorders in Brazil

Introduction: Inherited platelet disorders are rare conditions characterized by altered platelet function and/or reduced platelet counts. Diagnosing these disorders is challenging and may result in delays, misdiagnosis, and inappropriate treatment. In low- and middle-income countries, data are scarce. Here, we describe a cohort of patients at a reference center in Brazil. Methods: A descriptive analysis was conducted on patients followed at the Thrombosis and Hemostasis outpatient clinic of the Hospital das Clinicas, University of S & atilde;o Paulo, Brazil.Medical records of 857 patients with thrombocytopenia or bleeding disorders of unknown cause, evaluated between 1998 and 2023, were reviewed. Of these, 60 patients had a confirmed or suspected diagnosis of an inherited platelet disorder and were included in the study. Results: Among the 60 patients, the majority were female (75 %), with a median age of 48 years. The suspicion of a platelet disorder was based on clinical presentation, family history, and laboratory findings. Overall, 65 % of the patients had abnormal platelet function, while 35 % presented with thrombocytopenia. A positive family history was reported in 62 % of those with low platelet counts and in 51 % of patients with platelet function abnormalities. Previous misdiagnoses included immune thrombocytopenia and von Willebrand disease. Overall, the bleeding phenotype was mild, with a median ISTH-BAT (International Society on Thrombosis and Haemostasis Bleeding Assessment Tool) score of 6. Patients with reduced platelet counts tended to have lower ISTH-BAT score. Conclusions: Identifying inherited platelet disorders is essential for proper treatment and follow-up. This study emphasizes the need for careful assessment of family history, bleeding risk, platelet count, morphology, and function for diagnosis, particularly in low-resource settings without access to advanced genetic testing. (c) 2025 Associacao Brasileira de Hematologia, Hemoterapia e Terapia Celular. Published by Elsevier Espana, S.L.U. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).