Laboratory diagnosis of congenital and acquired coagulopathies, including challenging-to-diagnose rare bleeding disorders

Coagulation factors, anticoagulant proteins, and fibrinolytic proteins are important for haemostasis and may be altered by inherited and acquired conditions. Common causes of coagulopathies include vitamin K (VK) deficiency (VKD), liver disease, lupus anticoagulants, consumption or disseminated intravascular coagulation, and much less commonly, an inherited or an acquired autoimmune coagulopathy. VKD typically accounts for ≥30% of all coagulopathy referrals, and VKD is particularly common among infants but can occur at any age and in combination with other coagulopathies. Tests for fibrinogen help assess both congenital and acquired coagulopathies, with low levels predictive of poor outcomes from diverse conditions including trauma and postpartum haemorrhage. Inherited factor deficiencies are rarer, and some affect multiple coagulation factors (F), such as combined FV and FVIII deficiency, familial deficiencies of VK-dependent clotting factors, and congenital disorders of glycosylation.