Turkut, Tan, T.Parıltay, E.Avcı, Durmusaliogu, E.Isik, E.Çoğulu, O.Kavaklı, K.Atik, T.2024-08-252024-08-2520231538-7933https://doi.org/10.1016/j.jtha.2023.06.029https://hdl.handle.net/11454/101849Cerebral venous thrombosis (CVT) is a rare cerebrovascular disorder characterized by the obstruction of venous channels in the brain. Genetic factors play a significant role in CVT development, and recent studies have identified gain-of-function mutations in coagulation factors, including factor IX (FIX). This case report focuses on a unique neonatal case of CVT, where an X-chromosome duplication involving the F9 gene resulted in increased FIX activity. The neonate presented with feeding difficulties, weight loss, nystagmus, and seizures. Imaging and laboratory tests confirmed a 554-kb X-chromosome duplication encompassing the F9 gene. This genetic abnormality likely contributed to the elevated FIX activity level and subsequent CVT development. Understanding the relationship between coagulation factor abnormalities and CVT risk expands our knowledge of thrombophilia's genetic basis and may aid in the development of targeted treatment strategies for CVT management. © 2023 International Society on Thrombosis and Haemostasisen10.1016/j.jtha.2023.06.029info:eu-repo/semantics/closedAccesscerebral venous thrombosiselevated factor IX activityF9 gene duplicationgenetic risk factors in thromboembolismpediatric thrombophiliaArticle2-s2.0-8516622814837414287Q1