Mild hemophilia A

Mild hemophilia A is a form of hemophilia A, an inherited bleeding disorder caused by a deficiency or dysfunction of coagulation factor VIII (FVIII). In the mild form, individuals retain 5–40% of normal FVIII activity, which distinguishes it from moderate (1–5%) and severe (<1%) forms. The condition is caused by pathogenic variants in the F8 gene located on the X chromosome. Because it follows X-linked recessive inheritance, it predominantly affects males, while females are typically carriers, though some carrier females may experience mild bleeding symptoms. Mild hemophilia A primarily affects the hematologic system. Unlike severe hemophilia A, spontaneous bleeding episodes are uncommon. Instead, individuals with mild hemophilia A typically experience excessive or prolonged bleeding following surgery, dental procedures, or significant trauma. Symptoms may include prolonged bleeding from cuts, easy bruising, prolonged post-surgical bleeding, heavy bleeding after tooth extraction, and occasionally menorrhagia in female carriers. Joint and muscle bleeds (hemarthrosis and intramuscular hematomas), which are hallmarks of severe disease, are rare in the mild form. Because bleeding episodes are infrequent and often provoked, diagnosis may be delayed until adolescence or adulthood, sometimes not being identified until an unexpected bleeding event occurs during a surgical procedure. Treatment of mild hemophilia A centers on managing and preventing bleeding episodes. Desmopressin (DDAVP) is the first-line treatment for most patients with mild hemophilia A, as it stimulates the release of stored FVIII from endothelial cells, temporarily raising FVIII levels sufficiently to achieve hemostasis. A desmopressin challenge test is typically performed to confirm an adequate response before relying on this therapy. For patients who do not respond adequately to desmopressin or who require more sustained FVIII elevation (such as for major surgery), factor VIII replacement therapy using recombinant or plasma-derived FVIII concentrates may be used. Antifibrinolytic agents such as tranexamic acid or aminocaproic acid are often used as adjunctive therapy, particularly for mucosal bleeding and dental procedures. With appropriate management, individuals with mild hemophilia A generally have an excellent prognosis and a normal life expectancy.

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