Mutation analysis and clinical evaluation in patients diagnosed with GT and followed UP in OUR pediatric hematology clinic

Introduction and purpose: Glanzmann Thrombasthenia (GT) is a rare genetic platelet function disorder which is characterized by abnormal platelet aggregation. GT is an autosomal recessive disorder where the underlying problem is the lack or dysfunction of GpIIb/IIIa receptor on the platelet surface. This study aims at evaluating clinical and laboratory findings, determining genetic mutation typology and analyzing the association between mutation types and clinical findings for GT-diagnosed patients who are followed up in Yüzüncü Yıl University Medical School Pediatric Hematology Department. Materials and methods: In this retrospective study, file records of 17 GT patients, who have received treatment and follow-up by Yüzüncü Yıl University Dursun Odabaş Medical Center Pediatric Hematology Department between January 2008 and April 2018, have been investigated. The included patients' records have been reviewed carefully in terms of patient characteristics such as genetic mutations, age, gender, age of diagnosis, presenting symptoms, clinical findings, platelet count and volume. Bleeding findings have been evaluated using an up-to-date bleeding score. Results: Most frequent bleeding forms in patients were epistaxis, cutaneous bleeding and bleeding from minor injuries. Out of 12 patients with observed genetic mutation, six patients had the same mutation type. We found four novel mutations that have never been defined in the literature before. Out of these four mutations, three were placed in ITGA2B while the remaining one was in ITGB3 region. We found no significant association between genetic findings and clinical findings of patients. Conclusion: The single most frequent reason for apply to the hospital was mucocutaneous bleedings. Novel mutations were found in four cases of our study. No association found between patients' mutation types and patients' bleeding scores and bleeding phenotypes. Further and wide-range studies are required in order to explain the relationship between genotypes and clinical findings of GT patients.