Factor X deficiency: a comment on two recent case studies

Hereditary factor X deficiency (HFXD) is a rare genetic bleeding disorder, affecting approximately 1 in 1,000,000 individuals globally, and resulting in abnormally low activity of clotting factor X (FX). Diagnosis may occur early in life, particularly in patients with a family history of the disorder or severe deficiency, or later in life for those with mild-moderate deficiency. Regardless of age at diagnosis, this disorder can significantly impact the lives of patients, as well as those of caregivers and/or family members. Alongside a wide historical array of HFXD treatments, including supportive care with blood transfusions, FX replacement with fresh frozen plasma or prothrombin complex concentrates, specific replacement has been made possible with the isolation and concentration of human plasma-derived FX for therapeutic use, offering the potential for a streamlined prophylactic regimen and improved quality of life and wellbeing. Two recent case studies describe the diagnosis and management of children with HFXD in India and the Philippines, both of whom were diagnosed in infancy following severe bleeding episodes. They share important similarities but highlight key differences in the experience of diagnosis and management of HFXD. Together they illustrate the lack of a specific target population subgroup for this rare but serious bleeding disorders, and the importance of checking FX levels (among other clotting factors) when prothrombin time (PT) and partial thromboplastin time (PTT) are prolonged.