By: Dilan P, Zeph B, Ludwig A, and Carlos P

Genetic Transmission

People are born with hemophilia. Hemophilia is usually inherited, meaning that it is passed on through a parent’s genes.Sometimes hemophilia can occur when there is no family history of it. This is called sporadic hemophilia. About 30% of people with hemophilia did not get it through their parent’s genes. Hemophilia is a sex-linked recessive disease.

How is hemophilia inherited?

The hemophilia gene is passed down from parent to a child. The chromosome for hemophilia is the X chromosome. For this reason, hemophilia is called an X-linked (or sex-linked) disorder.

Women who have the hemophilia gene are called carriers. They sometimes show signs of hemophilia, and they can pass it on to their children. For each child, there is a 50% chance that a son will have hemophilia and a 50% chance that a daughter will carry the genes.

Women can only have hemophilia if their father has hemophilia and their mother is a carrier. It is very uncommon for this to occur though.

."How Do You Get Hemophilia?" - World Federation of Hemophilia. N.p., May 2012. Web. 09 Jan. 2015.


-In some cases, lengthy bleeding after circumcision

-Excessive bruising

-Swollen, painful joints

-Swollen, tender muscles

-Excessive bleeding from the gums, tongue, or mouth following injuries

-Severe bleeding after tooth extractions or other invasive dental procedures

-Severe bleeding after injuries or operations

"Understanding Hemophilia -- Symptoms." WebMD. WebMD, n.d. Web. 09 Jan. 2015.


Hemophilia A: 1 in 4,000 to 1 in 5,000 males worldwide.

Hemophilia B: 1 in 20,000 newborn males worldwide.

"Hemophilia." Genetics Home Reference. PubMed, Aug. 2012. Web. 07 Jan. 2015.


If doctors suspect hemophilia A or B in an adolescent, they will do some simple blood tests. They will take a blood sample, and measure the amount of Factor VIII and Factor IX in the blood.

- Factor VIII is the protein which is lacking in hemophilia A.

- Factor IX is the protein which is lacking in hemophilia B.

The tests will show:

- If the person has a bleeding disorder

- What kind of bleeding disorder the person has

- How severe the bleeding disorder is.

"The Diagnosis of Hemophilia." - Canadian Hemophilia Society. N.p., n.d. Web. 09 Jan. 2015.

Treatment and Life Expectancy

The main treatment for hemophilia is replacement therapy. Blood clotting factors are taken from donors and purified or from labs artificially. Then, the concentrate is infused into the patient’s blood. With proper treatment, life expectancy for people with hemophilia is about 69 years in the U.S. Without treatment, most don’t live to adulthood.

6 Interesting Facts

1. Hemophilia B is also known as Christmas disease. This name comes from Stephen Christmas, who was the first patient known to have this disease.

2. Nearly 90% of Americans with hemophilia were infected with AIDS in the 1980's when blood donations in the U.S. were not properly screened for HIV.

3. Treatments for hemophilia rank among the most expensive chronic disorders in the US ranging from $150,000 to $350,000 annually per patient.

4. About 1/3 babies with hemophilia have a new mutation not found in other family members.

5. About 70% of people with hemophilia have the the most common form, Hemophilia A, and 30% have hemophilia B.

6. Women who are carriers of the gene can pass it on through birth and have a 25% chance of having a son with hemophilia.

"Fast Facts." Fast Facts. Web. 21 Jan. 2015.

"Hemophilia Basics." WebMD. WebMD. Web. 21 Jan. 2015.


Dilan P.

Interesting facts