What is Haemophilia?
Haemophilia is a rare, inherited bleeding disorder where blood does not clot properly. This is due to low levels of specific blood proteins called clotting factors. In a healthy person, these factors work together with platelets to form a clot and stop bleeding. For a person with hemophilia, this clotting process is either delayed or doesn't happen, leading to prolonged bleeding after injury or spontaneous bleeding episodes.
There are two main types of the disease, each defined by which clotting factor is deficient.
The Misnomer of 'Royal Haemophilia'
The term 'Royal Haemophilia' is a historical nickname and not an official medical diagnosis. It gained prominence because the bleeding disorder affected several European royal families, particularly descendants of Britain's Queen Victoria, in the 19th and 20th centuries. Genetic analysis has confirmed that Queen Victoria was a carrier for Hemophilia B, also known as Christmas disease, not Hemophilia A. This means the historical 'Royal' disease was actually Christmas disease. The gene was passed to three of her children and subsequently spread through royal marriages across Europe.
Christmas Disease: A Specific Type of Hemophilia
Christmas disease is the historical name for Hemophilia B. It was named after Stephen Christmas, a young Canadian boy diagnosed in 1952, whose specific clotting deficiency led to the identification of Factor IX (9). This condition was initially called Christmas disease before being officially designated Hemophilia B.
Genetic Inheritance of Hemophilia A and B
Both Hemophilia A and Hemophilia B are typically inherited in an X-linked recessive pattern, primarily affecting males. The genes for clotting factors VIII and IX are located on the X chromosome. Males (XY) inherit one X chromosome from their mother. If this X chromosome carries the affected gene, they will have hemophilia. Females (XX) are often carriers but usually don't show severe symptoms due to having a functional gene copy on their other X chromosome.
Symptoms and Diagnosis
The symptoms for both Hemophilia A and B are similar and depend on the severity of the clotting factor deficiency. These can include excessive bleeding, frequent bruising, and bleeding into joints and muscles causing pain and swelling. Diagnosis is made through blood tests that assess clotting time and identify the specific missing factor.
Treatment and Management
Effective treatments are available to manage hemophilia and prevent complications, though there is currently no cure. Key strategies include replacing the missing clotting factor through infusions (factor replacement therapy), which can be preventative (prophylaxis) or used to stop bleeding episodes (on-demand therapy). Gene therapy is an emerging treatment, including options like Hemgenix® for Hemophilia B which may help the body produce its own factor. Physical therapy can also help manage joint damage.
Comparison Table: Hemophilia A vs. Hemophilia B
| Feature | Hemophilia A | Hemophilia B (Christmas Disease) |
|---|---|---|
| Missing Clotting Factor | Factor VIII | Factor IX |
| Historical Connection | Often mistakenly associated with royalty. | The actual 'Royal disease' passed down through Queen Victoria's lineage. |
| Prevalence | More common, approximately 1 in 5,000 male births. | Less common, approximately 1 in 25,000 male births. |
| Prevalence of Severe Cases | Higher proportion of severe cases. | Lower proportion of severe cases. |
| Inhibitor Development | Higher risk (20-30% of severe cases). | Lower risk (less than 3-10% of severe cases). |
| Gene Therapy | Newer options like Roctavian®. | FDA-approved gene therapy like Hemgenix® is available. |
Conclusion
Understanding the historical terms 'Royal haemophilia' and 'Christmas disease' alongside their modern medical names, Hemophilia A and Hemophilia B, is important for accurate information. Royal haemophilia is a historical nickname for the Hemophilia B that affected Queen Victoria's descendants. Christmas disease is the original name for Hemophilia B. Both are distinct genetic disorders with similar bleeding symptoms caused by deficiencies in different clotting factors, Factor VIII (Hemophilia A) and Factor IX (Hemophilia B). With advancements in treatment, individuals with either condition can lead healthy lives. For further details, the {Link: National Bleeding Disorders Foundation https://www.bleeding.org/} is a valuable resource.
