Rare inherited coagulation disorders in young children in Oman.

Background: Rare coagulation disorders represent 3-5% of all inherited coagulation deficiencies and are usually inherited as autosomal recessive. Oman has high rate of consanguineous marriages; we aimed to study the prevalence, presentation and management in affected Omani children. Materials and Methods: Retrospective study in pediatric patients with rare coagulation disorders in a tertiary hospital in Oman from 2009 to 2020. Results: Rare coagulation disorders were diagnosed in 79 patients (39 males/40 females), aged 1 day to 13 years, accounting for 24.7% (79/319) of all children with inherited coagulation disorders; remainder included patients with hemophilia and von Willebrand disease. FXI deficiency was most common with prevalence of 39.2%, followed by fibrinogen disorders 32.9%, FVII 18.9%, FV 5%, FXIII 2.5%, and FX deficiencies 1.2%. Manifestations ranged from mild to serious to rare/atypical; presentation at birth, ruptured-hemorrhagic ovarian cyst, splenic laceration-rupture, and sight-threatening retrobulbar-intraocular hemorrhage. Intracranial hemorrhage (ICH) occurred in 9/79 patients, it was initial mode of presentation in seven of them. Global developmental delay as a complication occurred in three. Standardized treatment strategies were used with prophylaxis initiation early in life in severely affected children. Conclusions: This ethnic group demonstrated unique features in terms of: heterogenous/atypical presentations; severe manifestations in moderate phenotype hypofibrinogenemia; clinical severity and laboratory phenotype correlation in FV deficiency; poor association between factor activity level and bleeding severity in FVII deficiency and severe bleeding tendency despite moderate laboratory phenotype in FXIII deficiency. We recommend multicenter collaboration to identify the genotype-phenotype correlation and therapeutic options of such rare, yet serious disorders.