1. Hemophilia
By Charlene Yan

2. What is it?
A group of hereditary disorders that impair the body’s ability to control blood clotting.
It is a recessive sex-linked disorder therefore it affects more males than females.

3. Causes
Hemophilia A is a recessive X-linked genetic disorder involving a lack of functional clotting Factor VIII and represents 80% of hemophilia cases.
Hemophilia B is a recessive X-linked genetic disorder involving a lack of functional clotting Factor IX. Comprises almost 20% of all cases.
Hemophilia C is an autosomal genetic disorder involving a lack of Factor XI. This is the least likely form.

5. Symptoms
A hemophiliac does not bleed more intensely than a normal person but bleeds for a longer time.
In severe hemophiliacs, even a minor injury can result in blood lost lasting days or weeks.
Children with mild to moderate hemophilia may not have any symptoms at birth except large bruises when they fall.

6. Life Expectancy
Before 1960s, treatment was not available so people only lived to 11 years.
Today, with treatment, males with hemophilia can live normally but with a lifespan 10 years shorter than a normal male.

7. History Hemophilia is also known as the “royal disease”
Can be traced back to Queen Victoria, who was a carrier of the disease
Two of Victoria’s daughters were carriers of the disease so they passed the disease on to the Spanish, German, and Russian royal families

8. Discovery of Disease Dr. John Conrad Otto
Discovered it in 1803, but he could not explain why affected males could pass the trait to unaffected daughters.
This was only described in 1813 by John Hay.

9. How Technology has advanced
In the 1970s, treatment for hemophilia was discovered.
The treatment for hemophilia includes the infusion of factors XIII, IX, or XI.
In the 1990s, scientists came up with the idea of injecting prophylaxis into children with hemophilia.
Prophylaxis prevents chronic bleeding.
Today, children with hemophilia can live normally.

10. Bibliography http://en.wikipedia.org/wiki/File:XlinkRecessive.jpg