A case report of congenital factor X deficiency in an adult patient.

Factor X deficiency is one of the rarest coagulation disorders representing 10% of all rare bleeding diseases with a frequency of 1:1,000,000. A 39-year-old male patient with no previous medical conditions was admitted to the hospital with a left carpal ganglion for surgical excision. Routine preoperative laboratory examination revealed a high international normalized ratio of 5.4 IU (0.8-1.1) and a prothrombin time of 72.2 s (10.9-13.6), with an isolated factor X level of less than 5%. Genetic testing for congenital factor X deficiency identified a homozygous mutation c.271 > A (p.Glu91). Vitamin K supplementation did not improve his international normalized ratio or increase factor X levels; hence, surgery was delayed. The patient was re-hospitalized to remove a wisdom tooth, during which fresh frozen plasma was administered. An allergic reaction complicated this procedure in the form of a rash on the body. As a result, the tooth was removed without active bleeding. This report presents a unique factor X deficiency case with limited treatment options to improve factor X levels after failed vitamin K administration and an allergic reaction to fresh frozen plasma. A physician's observation and ongoing follow-up were the only reasonable approaches in treating the patient with mild to moderate factor X deficiency due to lack of prothrombin complex concentrates or factor X replacement at the center at the time.