Overview
Moderate hemophilia B, also known as moderate Christmas disease or moderate factor IX deficiency, is a hereditary bleeding disorder caused by mutations in the F9 gene located on the X chromosome. This gene encodes coagulation factor IX, a critical protein in the intrinsic pathway of the blood clotting cascade. In moderate hemophilia B, factor IX activity levels range between 1% and 5% of normal. The condition primarily affects the hematologic system, leading to prolonged and excessive bleeding that can involve muscles, joints, and soft tissues. Unlike severe hemophilia B, spontaneous bleeding episodes are less frequent, but patients typically experience prolonged bleeding after trauma, surgery, or dental procedures, and may occasionally have spontaneous joint or muscle bleeds. Key clinical features include easy bruising, prolonged bleeding from cuts or injuries, bleeding after surgical or dental procedures, and occasional hemarthrosis (bleeding into joints) that can lead to chronic joint damage if inadequately managed. Hematomas in muscles and soft tissues may also occur. Women who carry the mutation are typically asymptomatic carriers, though some may experience mild bleeding symptoms. Treatment of moderate hemophilia B centers on replacement therapy with plasma-derived or recombinant factor IX concentrates, administered on-demand to control bleeding episodes or prophylactically in certain situations such as before surgery. Desmopressin (DDAVP) is not effective for hemophilia B, unlike hemophilia A. More recently, extended half-life recombinant factor IX products have become available, reducing the frequency of infusions. Gene therapy for hemophilia B has shown promising results in clinical trials, with some products now approved or in late-stage development, representing a potentially transformative treatment option. Comprehensive care through specialized hemophilia treatment centers, including physical therapy and monitoring for inhibitor development, remains essential for optimal patient outcomes.
X-linked recessive
Carried on the X chromosome; typically affects males more than females
Childhood
Begins in childhood, roughly ages 1 to 12
FDA & Trial Timeline
5 eventsAlhemo: FDA approved
routine prophylaxis to prevent or reduce the frequency of bleeding episodes in adult and pediatric patients 12 years of age and older with hemophilia B (congenital factor IX deficiency) with or without FIX inhibitors
Qfitlia: FDA approved
routine prophylaxis to prevent or reduce the frequency of bleeding episodes in adult and pediatric patients aged 12 years and older with hemophilia A or B with or without factor VIII or IX inhibitors
Beqvez: FDA approved
treatment of adults with moderate to severe hemophilia B (congenital factor IX deficiency) who: Currently use factor IX prophylaxis therapy, or; Have current or historical life-threatening hemorrhage, or; Have repeated, serious spontaneous bleeding episodes, and; Do not have neutralizing antibodies to adeno-associated virus serotype Rh74var (AAVRh74var) capsid as detected by an FDA-approved test
HEMGENIX: FDA approved
Treatment of adults with Hemophilia B (congenital Factor IX deficiency) who: currently use Factor IX prophylaxis therapy, or; have current or historical life-threatening hemorrhage, or; have repeated, serious spontaneous bleeding episodes
Idelvion: FDA approved
Indicated in children and adults with hemophilia B (congenital Factor IX deficiency) for the (1) on-demand control and prevention of bleeding episodes, (2) perioperative management of bleeding, and (3) routine prophylaxis to prevent or reduce the frequency of bleeding episodes.
Data sourced from FDA regulatory filings and ClinicalTrials.gov. Updated periodically.
Treatments
5 availableAlhemo
routine prophylaxis to prevent or reduce the frequency of bleeding episodes in adult and pediatric patients 12 years of age and older with hemophilia B (congenital factor IX deficiency) with or withou…
routine prophylaxis to prevent or reduce the frequency of bleeding episodes in adult and pediatric patients 12 years of age and older with hemophilia B (congenital factor IX deficiency) with or without FIX inhibitors
Qfitlia
routine prophylaxis to prevent or reduce the frequency of bleeding episodes in adult and pediatric patients aged 12 years and older with hemophilia A or B with or without factor VIII or IX inhibitors
Beqvez
treatment of adults with moderate to severe hemophilia B (congenital factor IX deficiency) who: Currently use factor IX prophylaxis therapy, or; Have current or historical life-threatening hemorrhage,…
treatment of adults with moderate to severe hemophilia B (congenital factor IX deficiency) who: Currently use factor IX prophylaxis therapy, or; Have current or historical life-threatening hemorrhage, or; Have repeated, serious spontaneous bleeding episodes, and; Do not have neutralizing antibodies to adeno-associated virus serotype Rh74var (AAVRh74var) capsid as detected by an FDA-approved test
HEMGENIX
Treatment of adults with Hemophilia B (congenital Factor IX deficiency) who: currently use Factor IX prophylaxis therapy, or; have current or historical life-threatening hemorrhage, or; have repeated,…
Treatment of adults with Hemophilia B (congenital Factor IX deficiency) who: currently use Factor IX prophylaxis therapy, or; have current or historical life-threatening hemorrhage, or; have repeated, serious spontaneous bleeding episodes
Idelvion
Indicated in children and adults with hemophilia B (congenital Factor IX deficiency) for the (1) on-demand control and prevention of bleeding episodes, (2) perioperative management of bleeding, and (3…
Indicated in children and adults with hemophilia B (congenital Factor IX deficiency) for the (1) on-demand control and prevention of bleeding episodes, (2) perioperative management of bleeding, and (3) routine prophylaxis to prevent or reduce the frequency of bleeding episodes.
Clinical Trials
View all trials with filters →No actively recruiting trials found for Moderate hemophilia B at this time.
New trials open frequently. Follow this disease to get notified.
Treatment Centers
8 centersBaylor College of Medicine Rare Disease Center ↗
Baylor College of Medicine
📍 Houston, TX
🏥 NORDStanford Medicine Rare Disease Center ↗
Stanford Medicine
📍 Stanford, CA
🔬 UDNNIH Clinical Center Undiagnosed Diseases Program ↗
National Institutes of Health
📍 Bethesda, MD
🔬 UDNUCLA UDN Clinical Site ↗
UCLA Health
📍 Los Angeles, CA
🔬 UDNBaylor College of Medicine UDN Clinical Site ↗
Baylor College of Medicine
📍 Houston, TX
🔬 UDNHarvard/MGH UDN Clinical Site ↗
Massachusetts General Hospital
📍 Boston, MA
🏥 NORDMayo Clinic Center for Individualized Medicine ↗
Mayo Clinic
📍 Rochester, MN
👤 Mayo Clinic Center for Individualized Medicine
🏥 NORDUCLA Rare Disease Day Program ↗
UCLA Health
📍 Los Angeles, CA
Financial Resources
2 resourcesTravel Grants
No travel grants are currently matched to Moderate hemophilia B.
Community
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Start the conversation →Latest news about Moderate hemophilia B
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Caregiver Resources
NORD Caregiver Resources
Support, advocacy, and financial assistance for caregivers of rare disease patients.
Mental Health Support
Rare disease caregiving can be isolating. Connect with counseling and peer support.
Family & Caregiver Grants
Financial assistance programs specifically for caregivers of rare disease patients.
Social Security Disability
Learn how rare disease patients may qualify for SSDI/SSI benefits.
Common questions about Moderate hemophilia B
What is Moderate hemophilia B?
Moderate hemophilia B, also known as moderate Christmas disease or moderate factor IX deficiency, is a hereditary bleeding disorder caused by mutations in the F9 gene located on the X chromosome. This gene encodes coagulation factor IX, a critical protein in the intrinsic pathway of the blood clotting cascade. In moderate hemophilia B, factor IX activity levels range between 1% and 5% of normal. The condition primarily affects the hematologic system, leading to prolonged and excessive bleeding that can involve muscles, joints, and soft tissues. Unlike severe hemophilia B, spontaneous bleeding
How is Moderate hemophilia B inherited?
Moderate hemophilia B follows a x-linked recessive inheritance pattern. Genetic counseling can help families understand recurrence risk and testing options.
At what age does Moderate hemophilia B typically begin?
Typical onset of Moderate hemophilia B is childhood. Age of onset can vary across affected individuals.
Which specialists treat Moderate hemophilia B?
12 specialists and care centers treating Moderate hemophilia B are listed on UniteRare, sourced from ClinicalTrials.gov principal investigators, published research, and the NPPES NPI registry.
What treatment and support options exist for Moderate hemophilia B?
3 patient support programs are currently tracked on UniteRare for Moderate hemophilia B. See the treatments and support programs sections for copay assistance, eligibility, and contact details.