Hemophilia is an umbrella term which describes a number of relatively rare heritable bleeding disorders. That’s still pretty complicated so lets break it down a little more.
A bleeding disorder, in this context, is a condition which prevents effective blood clotting in affected individuals. This does not mean that people with hemophilia bleed any more than unaffected individuals; it simply means that no effective clot will be formed to stop bleeding in a person with hemophilia. Left untreated, this means that minor wounds such as paper cuts will continue to ooze small amounts of blood, while more serious wounds or trauma can cause very serious sort or long term health issues.
Hemophilia is a genetic disorder, meaning that it is inherited from a persons parents, it is not contagious. Hemophilia can be caused by one of several mutations in the X chromosome. Because these mutations occur on the X chromosome hemophilia is most commonly observed in males (who only have one X chromosome). There are a few different varieties of hemophilia; the two most common are hemophilia A and hemophilia B. Hemophilia A is the most common, affecting about 1 in 5000 male births in the U.S. and is about four times as common as hemophilia B (NHF). The difference between the types of hemophilia is which aspect of the clotting process they affect, type A affects the clotting factor VIII while type B affects factor IX. Without going into too much detail about the clotting process, it works through a cascade of interactions between a number of different molecules, and if any one of these are absent the process will not work and no clot will form to stop the bleeding.
I will be exploring and explaining the science of hemophilia further in subsequent blog posts.
Some general information about bleeding disorders and helpful links.
The NIH does a great job of detailing all kinds of medical conditions, and hemophilia is no exception. Great for a brief overview of hemophilia if you are just starting to learn about it.
The national Hemophilia Foundation is the US organization in charge of information, education, and activism for hemophilia. A really great place to learn more and connect with other people.
The World Federation of Hemophilia is the international organization for people with bleeding disorders, their families, and their doctors. They are an invaluable source of information and they do great work.
The NHF guide to sports and activities for people with bleeding disorders. A really good resource for individuals and families looking for healthy forms of exercise for an individual with a bleeding disorder.