Hemophilia C is a rare, inherited blood disorder due to a deficiency of blood clotting protein Factor XI. It’s less severe than hemophilia A and B and is inherited differently. Still, it can cause excessive bleeding.

Hemophilia is a rare genetic disorder that prevents your blood from clotting properly. This can lead to heavy bleeding, which can be life threatening.

In healthy people, blood clots when there is damage to a blood vessel. Blood clotting is a complicated process that requires different protein molecules called clotting (or coagulation) factors. There are 13 clotting factors, numbered using Roman numerals from I to XIII.

Hemophilia occurs when there is a mutation (change) in one of the genes that make your clotting factors. There are several types of hemophilia, which doctors classify according to which clotting factor is affected. Hemophilia C results from a mutation in factor XI. It’s also called factor XI deficiency or Rosenthal syndrome.

In this article, we’ll talk about hemophilia C — its causes, symptoms, diagnosis, treatment, and outlook for people with this condition.

Hemophilia A, B, and C are all types of hemophilia caused by mutations in different clotting factors.

  • Hemophilia A: This condition occurs due to a mutation in factor VIII.
  • Hemophilia B: Also called Christmas disease, hemophilia B is due to a mutation in factor IX.
  • Hemophilia C: This condition happens when there is a mutation in factor XI.

According to the Centers for Disease Control and Prevention (CDC), both hemophilia A and B affect more people assigned male at birth than those assigned female. Both these conditions can cause severe symptoms associated with bleeding and bruising.

But hemophilia C affects all genders equally and can have little to no symptoms.

Hemophilia C results from a mutation in the F11 gene, which provides instructions for making factor XI. You can inherit this mutation from your parents. It prevents your body from making enough factor XI, leading to bleeding problems.

Hemophilia C is an autosomal disease. This means that the F11 gene responsible for this condition is not located in one of the sex chromosomes (X or Y). This is different from hemophilia A and B, both of which are the result of genes in the X chromosome.

Hemophilia C is also a recessive disease. This means you need two copies of the mutated F11 gene (one from each parent) to have symptoms. People with one copy are called carriers and can pass this condition to their children.

In rare cases, some people experience symptoms of hemophilia C with only one copy of the mutated gene.

How common is hemophilia C?

Hemophilia C is very rare. Experts estimate it affects only 1 out of 100,000 people in the world.

But some people may have a higher risk of developing this condition. For example, experts estimate that up to 8% of Ashkenazi Jews living in Israel have this disorder.

The symptoms of hemophilia C are usually mild. Many people with this condition may not experience any symptoms. Others typically develop symptoms in adulthood. People with uteruses may have more severe symptoms related to menstrual bleeding and childbirth.

The symptoms of hemophilia C can include:

Unlike hemophilia A and B, hemophilia C doesn’t typically cause spontaneous (unprompted) bleeding. Instead, bleeding may occur after an oral (mouth) surgery, for example, tooth extraction.

A doctor may suspect hemophilia based on your symptoms or if you’re related to someone with the condition.

To diagnose hemophilia C, a doctor called a hematologist will likely order a series of blood tests to look at your blood, its coagulation (clotting) properties, and the levels of clotting factors. These tests include:

They may also order a genetic test to confirm the diagnosis and identify the specific genetic mutation responsible for the disorder.

After confirming a diagnosis, your doctor may recommend genetic counseling, especially if you’re planning to have children.

People with hemophilia C usually don’t require treatment unless they’re undergoing surgery or have an injury that causes severe bleeding. When this happens, your medical team will try to get your factor XI to adequate levels. They can do this by using fresh frozen plasma from healthy blood donors and medications that keep clotting factors from breaking down.

Your doctor may also recommend specific lifestyle changes, such as avoiding contact sports and other activities that may increase the risk of injury. If you have heavy periods, they may recommend birth control that reduces menstrual bleeding.

Most people with hemophilia C live long, healthy lives with little to no symptoms.

Still, it’s essential to remember that, with hemophilia C, any bleeding can be potentially life threatening. It’s best to avoid injuries, if possible. Be sure to let your doctors and dentists know about your condition, especially if you’re planning to have surgery.

Hemophilia C is a rare bleeding disorder caused by a mutation in the F11 gene that makes clotting factor XI. It’s mostly an autosomal recessive genetic disorder, meaning you need two copies of the mutated gene to have the condition. Still, there are reported cases where people have hemophilia C with only one mutated gene.

Hemophilia C is different from other types of hemophilia. It’s a relatively mild condition that affects all genders equally. Many people with this condition may not know they are affected until they have a procedure, most often dental surgery.

Most people with hemophilia C don’t need treatment unless they have severe bleeding. Healthcare professionals can control the bleeding with fresh frozen plasma and certain medications.

Although hemophilia C is potentially life threatening, most people enjoy long and healthy lives. Still, it’s important to avoid activities that can cause injuries.