Hemophilia

Hemophilia is a disorder in which one of the 11 blood-clotting factors is missing or reduced, resulting in bruising and bleeding. Caused by a sex-linked defective gene, it affects about one in 5,000 boys born in the United States. Although hemophilia typically is inherited, a third of the cases may result from a new genetic mutation.

The most common type of hemophilia, caused by a lack of clotting factor VIII, is called hemophilia A or classic hemophilia. The second most common type is caused by a lack of clotting factor IX and is called hemophilia B or Christmas disease, named for Stephen Christmas, the first person diagnosed with the factor IX deficiency. Hemophilia A and B occur almost always in boys. A third, very rare type of hemophilia, called Hemophilia C, is caused by a lack of clotting factor XI and can occur in both girls and boys.

At UCSF Children's Hospital, the pediatric Hemophilia Treatment Center offers the most comprehensive care for children with hemophilia throughout Northern California. Through our research, we also provide the latest advances in treating complications of the disease.

For more information, please call:
Hemophilia Treatment Center (415) 476-4901

Reviewed by health care specialists at UCSF Children's Hospital.
Last updated May 8, 2007