Hemophilia B
- Deepti Kumar
- 2 minutes ago
- 3 min read
Did you know hemophilia B is also called Christmas disease? Despite the name, it has nothing to do with Christmas.
Stephen Christmas a 5-year old boy, born in England in 1947, used to get bruised easily and had been hospitalized nine times for hematomas i.e. his blood would collect outside a blood vessel. Initially he was diagnosed with classic hemophilia amongst variety of other conditions. But researchers looking into his case found that he lacked the clotting factor IX not VIII. The findings from this study were reported in 1952 in the British Medical Journal article titled “Christmas Disease: A condition previously mistaken for Hemophilia.”
What is hemophilia B?
Hemophilia B is a genetic disorder caused by the lack or low levels of clotting factor IX. Hence, the blood does not clot properly leading to spontaneous internal bleeding in the muscles, organs, and joints, and prolonged bleeding following surgeries or injury. According to the Center for Disease Control and Prevention (CDC), hemophilia B occurs in 1 in 19,283 male births in the US. This condition is more common in males than females.
Genetics behind hemophilia
Understanding the genetics of hemophilia can be empowering, if you suspect that a genetic predisposition for hemophilia exists in your family. Hemophilia is passed down from parents to their children. It is a sex-linked disorder, meaning the X and the Y chromosome determine its inheritance pattern. The gene for hemophilia is present on the X chromosome. It is inherited in a X-linked recessive manner. Females carry two X chromosomes, one from the mother and one from the father (XX). Males carry one X chromosome from the mother and one Y chromosome from the father (XY). If the son inherits hemophilia carrying gene from his mother he will have hemophilia. The father cannot pass on hemophilia to their sons. The daughter on the other hand has two copies of the X chromosome and so even if she inherits the hemophilia carrying gene from the mother, she has the healthy X chromosome from the father and will not have hemophilia.
Symptoms of hemophilia B
The main symptom is excessive bleeding due to the lack of normal levels of factor IX clotting protein. The symptoms can range from mild to severe. Common symptoms include:
Prolonged and or profuse bleeding after injury or surgery
Bruising easily
Sudden bleeding for no obvious reason like nose bleeds
Bleeding after minor injuries such as your baby bumps their head on a toy
Blood collecting under your baby’s skin after they have had a shot
Diagnosis
Your doctor will perform a physical exam, checking for symptoms like bruising, swollen or painful joints, bleeding. He or she will ask about family history of bleeding disorder or hemophilia. They can do blood test to check the levels of the clotting factor IX. Other tests include:
CBC
Prothrombin time (PT) test
Partial thromboplastin test
Fibrinogen test
Genetic tests to check for genetic cause
Treatment
The goal of treatment is to reduce the bleeding by helping your blot clot. This can be achieved by the following treatment options
Factor IX concentrate: This treatment replaces or supplements the lack or low levels of the factor IX clotting protein.
Medication: Your doctor may prescribe medications such as the Food and Drug Administration (FDA) approved drug concizumab-mtci to promote blood clotting and reduce the frequency of bleeding episodes.
Gene therapy: Hemgenix is a gene replacement therapy drug approved by the FDA that can be prescribed by your doctor. This treatment helps people make more factor IX by providing the gene for clotting factor IX.
Hemophilia B is a complex condition to understand. Being proactive and asking questions is very important. If you have been diagnosed with hemophilia B, it is important to be regular with your hematologist who can create a treatment plan considering your genetics and severity of the disease. This will help you manage the condition and live a healthy life.
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