Pb2299: clinical and laboratory characteristics of children with inherited thrombocytopenia in a single egyptian university hospital

Background: Inherited thrombocytopenias (IT) are rare bleeding disorders, which cause a deficiency of platelets in early infancy. This group of disorders is sometimes associated with abnormal phenotypes. ITs are being recognized with increasing frequency. The study of IT in children is difficult due to the heterogeneity of the patients and the rarity of each disease. To the best of our knowledge, the study of the epidemiology of such a hematological finding in our area has not been previously published. Aims: To report the clinical and laboratory characteristics of children with inherited thrombocytopenia. Methods: The files of all children with thrombocytopenia followed at the Hematology clinic of Alexandria University Children’s Hospital, Alexandria, Egypt, were retrospectively analysed. Patients who joined the clinic until the 31st of December 2021 were included. IT was considered in patients with suggestive clinical features as young age of presentation, abnormal physical features, positive family history, no response to ITP drugs. The blood film was revised for assesment of platelet size and morphology. Flowcytometry of platelet glycoproteins was perfromed. Results: Forty patients were identified as suspected IT. The median age of patients was 65 months, ranging from 9 months to 17 years at the time of the study. Thrombocytopenia was first discovered at a median age of 20 months. Fifty-five percent were males. In 55% of patients, there was a history of thrombocytopenia in a family member, and 42% had consanguineous parents (first-degree cousins). The most common bleeding symptoms were purpura and ecchymoses, followed by mucosal bleeding. The median platelet count at diagnosis was 30 ×103 cell/uL, while the lowest was 9 ×103 cell/uL. The initial recorded diagnosis was ITP in 65% of patients, followed by Glanzmann thrombasthenia (7.5%), CAMT and WAS (5% each). After revision of the diagnosis, BSS was confirmed in 20% of patients, WAS in 12.5%; some rare disorders were identified like MYH9-RD and Glanzmann thromboasthenia with macrothrombocytopenia. In 35% of patients the diagnosis was not defined yet. Seven patients were missing for further workup, and seven patients were sent for genetic testing. Summary/Conclusion: Inherited thrombocytopenias are rare disorders that are frequently overlooked. A detailed family and disease history, examination of the blood film by an expert, and assessment of the response to usual ITP treatments are all simple methods that help pick up suspected cases. Simple tests like platelet glycoprotein flowcytometry or MYH9 staining can confirm the diagnosis in a substantial number of patients. Genetic tetsing is the final step for undiagnosed cases.