Constitutional Factor XIII Deficiency in a Young Adult: A Case Report

Abstract

Constitutional factor XIII deficiency is a rare inherited coagulation disorder, with an estimated worldwide prevalence of approximately 1 case per 2 million individuals. It is transmitted in an autosomal recessive pattern, and homozygous or compound heterozygous forms are associated with a characteristic bleeding phenotype, often marked by delayed hemorrhage after trauma and specific bleeding sites. We report a case diagnosed at the Central Hematology Laboratory of Ibn Sina University Hospital in Rabat. A 21-year-old patient was admitted to the medical emergency department with a dark bluish thigh hematoma associated with painful muscle contraction, swelling sensation, and limited knee flexion. The patient had previously been managed as having hemophilia A; however, administration of factor VIII, even at high doses, resulted in no clinical improvement. Repeated hemostasis testing showed normal coagulation screening results, with a prothrombin time of 71% and a normal activated partial thromboplastin time ratio of 1. Coagulation factor assays, including anti-hemophilic factors VIII and IX, were within normal ranges, except for factor XIII activity, which was markedly reduced at 2.5% compared with a normal range of 70–140%. Family history revealed factor XIII deficiency in the patient’s younger brother, who had presented with bleeding after umbilical cord separation during the neonatal period. Based on these findings, a diagnosis of isolated factor XIII deficiency was established.Congenital factor XIII deficiency should be considered in patients presenting with unexplained hematomas, hemarthroses, or bleeding manifestations despite normal routine coagulation tests, particularly when there is no response to factor replacement therapy.