FAQs

About Hemophilia, Von Willebrand and Rare Diseases
HEMOPHILIA
Hemophilia is a mostly inherited genetic disorder that impairs the body's ability to make blood clots, a process needed to stop bleeding. This results in people bleeding longer after an injury, easy bruising, and an increased risk of bleeding inside joints or the brain. Those with a mild case of the disease may have symptoms only after an accident or during surgery. Bleeding into a joint can result in permanent damage while bleeding in the brain can result in long term headaches, seizures, or a decreased level of consciousness.
HEMOPHILIA A
It is an inherited hemorrhagic disorder caused by a lack of blood coagulation factor VIII. Without enough of this factor, blood cannot be properly clotted to stop bleeding

Causes
When bleeding, a series of reactions are performed on the body to help form blood clots. The process is called a coagulation cascade. Involves special proteins called coagulation factors or coagulants. You may have an increased risk of bleeding excessively if one or more of these factors are missing or not working as they should.

Factor VIII (eight) is 1 of such coagulation factors. Hemophilia A is the result of the inability of the body to produce enough factor VIII.

Hemophilia A is caused by an X-linked recessive hereditary trait with the defective gene located on the X chromosome. Females have 2 copies of the X chromosome. If the factor VIII gene on 1 of the chromosomes does not work, the gene on the other chromosome can do the job of producing enough factor VIII.

If a woman has a defective factor VIII gene, she is considered a carrier, which means that she can pass on that defective gene to her children. Children born to these women have a 50% chance of developing hemophilia A and girls have a 50% chance of being carriers. All daughters of hemophiliacs are carriers of the defective gene. Risk factors for hemophilia A include:

• Family history of bleeding
• Being a man
HEMOPHILIA B
It is an inherited bleeding disorder caused by a lack of blood clotting factor IX. Without enough of this factor, the blood can’t properly clot to control bleeding.

Causes
When bleeding, a series of reactions are performed on the body to help form blood clots. The process is called a coagulation cascade and involves special proteins called coagulation factors or coagulants. You may have an increased risk of bleeding excessively if one or more of these factors are missing or not working as they should.
Factor IX (nine) is 1 of such coagulation factors. Hemophilia B is the result of the inability of the body to produce sufficient factor IX. Hemophilia B is caused by an X-linked recessive hereditary trait, with the defective gene located on the X chromosome.
Women have 2 copies of the X chromosome. If the factor IX gene on 1 of the chromosomes does not work, the gene on the other chromosome can do the job of producing enough factor IX.
Men have only 1 X chromosome. If the factor IX gene is missing on a child's X chromosome, he will have hemophilia B. For this reason, most people with hemophilia B are men.
If a woman has a defective factor IX gene, she is considered a carrier, which means that she can pass on that defective gene to her children. Children born to these women have a 50% chance of developing hemophilia B and girls have a 50% chance of being carriers.
All daughters of hemophiliacs are carriers of the defective gene.

Risk factors for hemophilia B include:

• Family history of bleeding
• Being a man

VON WILLEBRAND DISEASE

Von Willebrand disease (vWD), discovered by Erik Adolf von Willebrand, is the most common hereditary blood-clotting disorder in humans. An acquired form can sometimes result from other medical conditions.

Causes

VIt arises from a deficiency in the quality or quantity of von Willebrand factor (vWF), a multimeric protein that is required for platelet adhesion. It is known to affect humans and several breeds of dogs. The three forms of vWD are: hereditary, acquired, and pseudo or platelet type. The three types of hereditary vWD are: vWD type 1, vWD type 2, and vWD type 3. Type 2 contains various subtypes. Platelet type vWD is also an inherited condition.

vWD type 1 is the most common type of the disorder which is typically asymptomatic, though mild symptoms such as nosebleeds may occur, and occasionally more severe symptoms. Blood type can affect the presentation and severity of symptoms of vWD.

vWD type 2 is the second most common type of the disorder and has mild to moderate symptoms.

RARE DISEASES
Rare diseases are those that have a low incidence in the population. To be considered as rare, each specific disease can only affect a limited number of people, specifically, when it affects less than 5 out of every 10,000 inhabitants.
However, rare diseases affect a large number of people, according to the World Health Organization (WHO), there are about 7,000 rare diseases affecting 7% of the world's population. In total, it is estimated that in Spain there are more than 3 million people with rare diseases.

For this reason, anyone can suffer a rare disease, at any stage of life.

Rare diseases:
• May include chronic illness, disability, and often premature death.
• Often have no treatment or is not very effective.
• Frequently not correctly diagnosed.
• Often very complex.
• They are caused frequently by changes in the genes.
It can be difficult to find a specialist who knows how to treat your rare disease. Disease support groups, rare disease organizations and genetics clinics can help you find one.
Source: https://en.wikipedia.org