Chromosomal and Genetic Conditions


What is hemophilia?

Children with hemophilia do not have enough of certain proteins that help their blood clot, so they may bruise or bleed easily.

For most people with the disease, small wounds are not a problem.

People with a mild case may not even know they have hemophilia until a major injury or a surgery causes severe bleeding. But bleeding that starts inside the body, whether from injury or disease, may be a danger.

Blood that collects inside the body can cause swelling and pain, and can damage nearby tissue.

Some people with hemophilia have problems with bleeding and pain in their joints. Bleeding can even deform the joints.

Other dangers are bleeding inside the skull that puts pressure on the brain, and bleeding that causes swelling that blocks the airway.

The disease is divided into two types, based on which proteins are too low:

Hemophilia A (Factor 8 deficiency)

Type A hemophilia occurs in children who do not have enough of the protein called Factor VIII (Factor 8).

Hemophilia B (Factor 9 deficiency)

Type B hemophilia occurs in children who do not have enough of the protein called Factor IX (Factor 9).

Hemophilia in Children

Hemophilia happens when a certain gene does not work right. In most cases, the disease is passed down from parents to children (genetic).

Only males can have the disease, but females can carry the gene that causes it. Mothers can pass this gene to their sons, who then may have the disease, or to their daughters, who then carry the gene themselves.

If a woman has the gene, there's 50% chance her son will have the disease and a 50% chance her daughter will carry the gene.

If a man has hemophilia, his son will not have the disease unless, by chance, the boy's mother passed the gene to him. The gene for hemophilia does not live on the chromosome that boys get from their father.

A man with hemophilia who has a daughter will pass the gene to her, so she will carry the gene for the disease.

In some cases, hemophilia happens even though there is no known family history. Most of the time when this happens, it turns out the child's mother carries the gene but did not know it.

Hemophilia at Seattle Children's

Seattle Children's is a Hemophilia Treatment Center. We offer a full range of services to diagnose and treat this disease. We can also counsel parents who have this disease (or trait) and want to know more about their risk of passing it down to their children (called genetic counseling).

Together with the Adult Hemophilia Treatment Center at Puget Sound Blood Center, we provide 24-hour telephone service by hemophilia nurse specialists who can give advice to patients with hemophilia or their parents.

We also provide coverage by doctors each summer for the yearly week-long hemophilia family camp called Camp I-Vy.

Read more about our experience and treatment of blood diseases through our Hematology Program.