Hemophilia B (Christmas Disease)

Description of the Disease

Hemophilia B (Christmas disease) is an X-linked recessive inherited bleeding disorder caused by a deficiency of clotting factor IX. Mutations in the factor IX gene occur less frequently than mutations causing hemophilia A (factor VIII deficiency), accounting for approximately 8–15% of all hemophilia cases. The disease primarily affects males, while females are usually asymptomatic carriers. An affected father does not pass the disease to his sons, but all of his daughters become carriers. Carrier daughters may then have sons with hemophilia and daughters who are also carriers.

Symptoms

The symptoms of all forms of hemophilia are similar, so laboratory testing is required to identify the specific clotting factor deficiency. The most characteristic symptom is bleeding into the skin, joints, muscles, gums, nose, gastrointestinal tract, and genitourinary tract. Severe bleeding following trauma, major wounds, intracranial hemorrhage, or bleeding into internal organs may lead to hemorrhagic shock and requires immediate medical attention.

The severity of bleeding depends on the level of clotting factor IX in the blood. When factor IX activity is less than 1%, the disease is considered severe, and spontaneous bleeding is common. When factor IX activity is greater than 5%, the disease is considered mild and usually presents with prolonged bleeding after minor injuries or surgical procedures.

In newborns, hemophilia may be suspected if cephalohematomas develop or if prolonged bleeding occurs from the umbilical stump or after injections. Excessive bleeding during teething is uncommon, but bleeding caused by injuries to the oral mucosa is relatively frequent.

Symptoms often become more apparent when children begin walking, as falls and minor trauma may result in extensive bruising, particularly around the head, eyes, buttocks, and genital area. The knees, ankles, and elbows are the joints most commonly affected.

Joint involvement may present as:

• Acute hemarthrosis: Sudden severe joint pain accompanied by swelling, redness, warmth, and tense skin over the joint. Pain usually subsides rapidly after appropriate factor replacement therapy or joint aspiration when indicated.
• Chronic hemophilic arthropathy: Recurrent bleeding into the joints gradually damages the cartilage, causes synovial membrane thickening and overgrowth, and eventually leads to bone destruction.
• Secondary rheumatoid syndrome: Symmetrical inflammatory arthritis affecting joints that have not previously bled. These joints become painful, deformed, and are often associated with morning stiffness.

Diagnosis

Diagnosis includes a complete blood count, platelet count, coagulation studies, bleeding time, clotting time, thrombin and prothrombin tests, and measurement of factor IX activity. In families with a history of hemophilia, female relatives may undergo DNA analysis and genetic testing to identify carrier status. Prenatal diagnosis can be performed by chorionic villus sampling at 10–12 weeks of pregnancy or by amniocentesis after 15 weeks of gestation, although the latter has limited sensitivity.

Treatment

Treatment consists of replacement therapy with factor IX concentrates, usually administered every 12–24 hours, with the dose determined by the patient’s body weight and the severity of bleeding. During joint bleeding, the affected joint should be immobilized for 2–3 days or supported with a compression bandage. Ice packs may be applied for 3–5 minutes at a time, and the affected limb should be kept elevated during the first few days. Other bleeding complications are managed with appropriate supportive and injury-specific treatment.

Source | Author Doctor Nikas Samuolis, reviewed by Prof. Virginijus Šapoka | Vilnius University | Faculty of Medicine | Head of the Department of Internal Medicine, Family Medicine, and Oncology