Hemophilia is an inherited bleeding disorder in which a person lacks or has low levels of certain proteins called “clotting factors” and the blood doesn’t clot properly as a result. This leads to excessive bleeding. There are 13 types of clotting factors, and these work with platelets to help the blood clot. Platelets are small blood cells that form in your bone marrow. According to the World Federation of Hemophilia (WFH), about one in 10,000 people are born with this disease.
People with hemophilia bleed easily, and the blood takes a longer time to clot. People with hemophilia can experience spontaneous or internal bleeding and often have painful, swollen joints due to bleeding into the joints. This rare but serious condition can have life-threatening complications.
The three forms of hemophilia are hemophilia A, B, and C.
Hemophilia A is the most common type of hemophilia, and it’s caused by a deficiency in factor VIII. According to the National Heart, Lung, and Blood Institute (NHLBI), eight out of 10 people with hemophilia have hemophilia A.
Hemophilia B, which is also called Christmas disease, is caused by a deficiency of factor IX.
Hemophilia C is a mild form of the disease that’s caused by a deficiency of factor XI. People with this rare type of hemophilia often don’t experience spontaneous bleeding. Hemorrhaging typically occurs after trauma or surgery.
Hemophilia is an inherited genetic condition. This condition isn’t curable, but it can be treated to minimize symptoms and prevent future health complications.
In extremely rare cases, hemophilia can develop after birth. This is called “acquired hemophilia.” This is the case in people whose immune system forms antibodies that attack factors VIII or IX.
The extent of your symptoms depends on the severity of your factor deficiency. People with a mild deficiency may bleed in the case of trauma. People with a severe deficiency may bleed for no reason. This is called “spontaneous bleeding.” In children with hemophilia, these symptoms may occur around age 2.
Spontaneous bleeding can cause the following:
- blood in the urine
- blood in the stool
- deep bruises
- large, unexplained bruises
- excessive bleeding
- bleeding gums
- frequent nosebleeds
- pain in the joints
- tight joints
- irritability (in children)
The following symptoms constitute a medical emergency. You should get treatment right away for any of these symptoms:
- a severe headache
- vomiting repeatedly
- neck pain
- blurred or doubled vision
- extreme sleepiness
- continuous bleeding from an injury
If you’re pregnant, it’s important that you see a doctor if you experience any of the above symptoms.
A process in your body that’s known as “the coagulation cascade” normally stops bleeding. Blood platelets coagulate, or gather together at the wound site, to form a clot. Then the body’s clotting factors work together to create a more permanent plug in the wound. A low level of these clotting factors or the absence of them causes bleeding to continue.
Hemophilia and Genetics
Hemophilia is an inherited genetic condition, meaning it is passed down through families. It’s caused by a defect in the gene that determines how the body makes factors VIII, IX, or XI. These genes are located on the X chromosome, making hemophilia an X-linked recessive disease.
Each person inherits two sex chromosomes from their parents. Females have two X chromosomes. Males have one X and one Y chromosome.
Males inherit an X chromosome from their mother and a Y chromosome from their father. Females receive an X chromosome from each parent. Because the genetic defect that causes hemophilia is located on the X chromosome, fathers can’t pass the disease to their sons. This also means that if a male gets the X chromosome with the altered gene from his mother, he’ll have hemophilia. A female with one X chromosome that has the altered gene has a 50 percent chance of passing that gene to her children, male or female.
A female who has the altered gene on one of her X chromosomes is typically called a “carrier.” This means she may pass the disease to her children but she doesn’t have the disease herself. This is because she has sufficient clotting factors from her normal X chromosome to avoid serious bleeding issues. However, females who are carriers often have an increased risk of bleeding.
Males with an X chromosome that has the altered gene may pass it on to their daughters, making them carriers. A female must have this altered gene on both of her X chromosomes to have hemophilia. However, this is very rare.
Risk Factors for Inheriting Hemophilia
Hemophilia A and B are more common in males than females because of genetic transmission.
Hemophilia C is an autosomal inherited form of the disease, meaning that it affects males and females equally. This is because the genetic defect that causes this type of hemophilia isn’t related to sex chromosomes. According to the Indiana Hemophilia and Thrombosis Center, this form of the disease most commonly affects people of Ashkenazi Jewish descent, but it may affect other ethnic groups as well. In the United States, hemophilia C affects about 1 in 100,000 people.
Hemophilia is diagnosed through a blood test. Your doctor will remove a small sample of blood from your vein and measure the amount of clotting factor present. The sample is then graded to determine the severity of the factor deficiency:
- Mild hemophilia is indicated by a clotting factor in the plasma that’s between 5 and 40 percent.
- Moderate hemophilia is indicated by a clotting factor in the plasma that’s between 1 and 5 percent.
- Severe hemophilia is indicated by a clotting factor in the plasma of less than 1 percent.
The complications of hemophilia include:
- joint damage from repetitive bleeding
- deep internal bleeding
- neurological symptoms from bleeding within the brain
You’re also at an increased risk of developing infections, such as hepatitis, when you receive donor blood.
Your doctor can treat hemophilia A with a prescription hormone. This hormone is called desmopressin, which they can give as an injection into your vein. This medication works by stimulating the factors responsible for the process of blood clotting.
Your doctor can treat hemophilia B by infusing your blood with donor clotting factors. Sometimes, the factors may be given in the synthetic form. These are called “recombinant clotting factors.”
Your doctor can treat hemophilia C using plasma infusion. The infusion works to stop profuse bleeding. The deficient factor responsible for hemophilia C is only available as a medication in Europe.
You can also go to physical therapy for rehabilitation if your joints are damaged by hemophilia.
Hemophilia is a condition that’s passed from a mother to her child. When you’re pregnant, there’s no way of knowing whether your baby has the condition. However, if your eggs are fertilized in a clinic using in vitro fertilization, they can be tested for the condition. Then, only the eggs without hemophilia can be implanted. Preconception and prenatal counseling can also help you understand your risk of having a baby with hemophilia.