Hemophilia B

Hemophilia B, once known as Christmas disease, is a rare inherited blood disorder. It causes excessive or unusual bleeding. People with this disease don’t have the usual amount of factor IX, a blood protein that helps your blood clot. It may be called factor 9 or FIX.

Symptoms of hemophilia B

The primary symptom is excessive bleeding because you don’t have the normal amount of factor 9 in your blood plasma. Factor 9 is measured in international units per deciliter (IU/dl).

Healthcare providers classify hemophilia (pronounced “hee-muh-FIL-ee-uh”) B and symptoms by factor 9 levels. Condition type and symptoms range from mild to severe.

People with mild forms of the condition may not have symptoms until they’re adults. People with moderate or severe hemophilia B may first experience symptoms when they’re babies. Common symptoms may include:

• Bleeding more than expected or longer than usual after surgery, after having a tooth pulled or if you have a serious injury
• Bruising very easily
• Bleeding for no obvious reason, like having a sudden nosebleed
• Big lumps if your baby bumps their head
• Bleeding after minor injuries, like if your baby bumps their mouth on a toy
• Blood pooling under your baby’s skin after they have had shots
• Bruises and swollen areas on their bodies that hurt your child when you touch the spot (which may mean they’re bleeding into a joint or muscle)
• Difficulty breathing if bleeding makes your child’s tongue swell

Hemophilia B causes

Hemophilia B typically happens when you inherit a changed F9 gene. This gene carries the instruction manual for making clotting factor 9. Changes in the gene cause low or missing clotting factor 9 levels. You inherit this condition in an X-linked recessive manner. Here’s how that happens:

• The changed genes that cause hemophilia B are on X chromosomes. Chromosomes decide your sex.
• Females have two X chromosomes. They inherit one from their biological mother and one from their biological father. Males inherit one X chromosome from their biological mother and one Y chromosome from their biological father.
• A biological mother with a changed factor 9 gene on one chromosome can pass that chromosome on to a biological child.
• A male child who inherits a chromosome carrying the changed factor 9 gene will have hemophilia B.
• A female child who inherits the changed gene will carry the disease, but they won’t have hemophilia symptoms. That’s because the second chromosome doesn’t carry the changed gene.

Hemophilia B may also happen through spontaneous mutation. In spontaneous mutation, the embryo created when an egg and sperm combine starts to divide and produce more cells. The new cells contain copies of the genes in the single cell. Mistakes or changes can happen during the gene-copying process. If there was a mistake when the F9 gene was copied, your child may have hemophilia B or carry hemophilia B.

How doctors diagnose hemophilia B

Healthcare providers will do a physical exam. They’ll check for symptoms like bruising and swollen or painful joints. They’ll ask if anyone in your biological family has hemophilia or another blood disorder.

They may do a blood test to check your factor 9 levels. Other tests may include:

• CBC
• Prothrombin time (PT) test
• Partial thromboplastin test
• Fibrinogen test
• Genetic tests to check for the genetic change that causes the condition

Your provider may recommend carrier screening if you’re pregnant. You may work with a genetic counselor to understand how hemophilia B may affect your family.

How is hemophilia B treated?

Healthcare providers treat this condition with medications that reduce bleeding by helping your blood clot. Examples are:

• Factor IX concentrate: This treatment replaces missing or low levels of factor IX.
• Medication: You may receive medication that helps your body form blood clots. Blood clots slow down bleeding.
• Gene therapy: This treatment uses lab-made normal copies of the F9 genes to help your body make normal factor IX.

When should I seek care?

Mild forms of hemophilia B may cause unusual bleeding. Women who have unusually long periods should check with their gynecologist. And check with a healthcare provider if you have bruises that happen for no obvious reason, or the bruises don’t go away.

Talk to your child’s pediatrician if you notice your baby bruises easily or they have nosebleeds for no apparent reason.

Many things cause these issues. Not all of them are hemophilia B. But it’s a good idea to check out unusual bleeding or bruising.

What can I expect if I have this condition?

There’s no cure for hemophilia B. But there are treatments to prevent or ease symptoms and improve your quality of life. The disease can cause issues that affect your health or lifespan. For example, you may have issues with your hips or knees if severe hemophilia causes bleeding into joints or muscles.

It’s not easy living with a chronic illness like hemophilia B. There are things you can do to protect your health:

• Avoid pain medications like aspirin or ibuprofen that interfere with blood clotting.
• Protect yourself from infection.
• Manage your weight.
• Ask your provider about steps you should take to avoid injuries that may trigger bleeding.
• Manage your stress.

You should see your healthcare provider for your regular treatment, any unusual bleeding or symptoms like severe joint pain.

What can I expect if my child has hemophilia B?

Your child’s needs will vary depending on their situation. Here are factors to consider if your child has moderate hemophilia:

• Pay close attention to safety straps on highchairs and car seats. Keeping your little one safely strapped in reduces the risk of minor injuries that could cause unusual bleeding.
• Make sure their caregivers and teachers know what to do if your child is hurt and starts to bleed.
• Ask your child’s pediatrician about activities your child should avoid. Ask about things they can do instead.

Children who have severe hemophilia B will need medical treatment for the rest of their lives. You may need to put protective covering on sharp edges of furniture. They may need to wear protective gear like kneepads for playtime. Kneepads and other protective gear may protect against bumps that can cause internal bleeding.

Your child may have issues living with a chronic disease. They may feel angry or frustrated if medical appointments make them miss activities or time with friends. Your child may benefit from counseling or support from a child life specialist.

How did hemophilia B get the name Christmas disease?

The disease was named after Stephen Christmas, a 5-year-old boy who was the first person diagnosed with hemophilia B after blood tests detected the protein now known as Factor 9.