Hemophilia Facts

Hemophilia is one of the inherited disorders of coagulation that causes abnormal bleeding or exaggerated and weak blood clots.
Hemophilia A and B are inherited in an inherited relational pattern associated with X, so men are usually affected, while women are generally carriers of the disease.
Hemophilia A is the cause of the lack of thrombotic factor VIII, while hemophilia B (also called Christmas sickness) is caused by the lack of factor IX.
Hemophilia varies in severity among affected people.
Symptoms include excessive bleeding from anywhere in the body. The long-term damage to the joints of recurrent hemorrhagic episodes is a characteristic feature.
The treatment involves the replacement factor of the coagulation therapy.
The formation of inhibitors for the treatment agent focuses on the significant complication of the treatment.
Genetic therapeutic remedies are a source of active research and promises for the future.

What is hemophilia?

Hemophilia is not a single disease, but one of a variety of hereditary bleeding disorders that cause abnormal bleeding or exaggerated and weak blood clotting. The term is commonly known as two specific conditions known as A. hemophilia and hemophilia B, which will be the main topics of this article. Hemophilia A and B are characterized by the specific gene that has been mutated (altered to become defective) and the symbols of a coagulation factor (protein) in each disease. Hemophilia C (deficiency in factor XI) is rarely found, but its effect on coagulation is much less pronounced than A or B.

Hemophilia A and B are inherited in an inherited relational pattern associated with X and, therefore, are more common in men. This inheritance pattern means that a particular gene on the X chromosome is expressed only when there are no normal genes present. For example, a child has only one X chromosome, so a child with hemophilia has defective genes on its single X chromosome (and is said to have hemophilic hemophilia). Hemophilia is the most common genetic disease associated with X.

Although it is more rare, the child may have hemophilia, but must have defective genes on each of their X chromosomes or have a single hemophilia gene plus an incorrect or defective copy of the second X chromosome that must carry normal genes. If the girl has a copy of the defective gene on one of her X chromosomes and on the other normal X chromosome, she has no hemophilia, but is said to be heterozygous (carrier). Their male children have a 50% chance of inheriting transgenic X genes, thus having a 50% chance of inheriting hemophilia from the pregnant mother.

Hemophilia A occurs in approximately 1 in 5,000 live male births. Hemophilia A and B occur in all ethnic groups. Hemophilia A is approximately four times more common than B. B. Occurs in approximately 1 in 20 000 births of live males.

Hemophilia has been called a real disease because Queen Victoria, Queen of England from 1837 to 1901, was the carrier. His daughters passed on transgenic genes to members of the royal family in Germany, Spain and Russia. Alexandra, granddaughter of Queen Victoria, who became Tsarina of Russia at the beginning of the 20th century when she married Tsar Nicholas II, was the transporter. His son, Alexei Tsarevich, suffered from hemophilia.

What causes hemophilia?


As mentioned above, hemophilia is caused by a genetic mutation. Mutations include genes that code for proteins that are essential in the blood’s clotting process. Bleeding symptoms appear due to poor blood clotting.

The process of blood coagulation involves a series of complex mechanisms involving 13 different proteins, factors classically called through XIII and written with Roman numerals. If the lining of the blood vessels is damaged, platelets are recruited into the affected area to form an initial plug. These published blood plates release chemicals that start the clotting sequence, activating a series of 13 proteins known as coagulation factors. Eventually, the fibroblast, the protein that intertwines with itself, forms to form a network that forms the final blood clot. The protein involved with hemophilia A is factor VIII (factor 8) and hemophilia B is factor IX (factor 9).
Hemophilia A is the cause of a mutation in the factor VIII gene, so there is a deficiency in this coagulation factor. Hemophilia B (also called Christmas sickness) is the result of a lack of factor IX due to a mutation in the corresponding gene.

Hemophilia A is more common than hemophilia B. Approximately 80% of people who suffer from hemophilia have hemophilia A. Hemophilia B occurs in about 1 in 20,000 to 30,000 people. A subset of people suffering from hemophilia B has a so-called leiden phenotype, which is characterized by severe childhood hemophilia that improves at puberty.

What are the signs and symptoms of hemophilia?

Hemophilia can vary in severity, depending on the particular type of mutations (genetic defect). The degree of symptoms depends on the levels of the affected coagulant factor. Severe disease is defined as <1% of activity factor, 1% to 5% of activity factor is moderate disease and more than 5% of activity factor is mild disease. The degree of hemorrhage depends on its severity (the amount of activity of the agent) and is similar to hemophilia A and B.

With severe hemophilia (A or B), bleeding begins at an early age and can occur spontaneously. Those who suffer from mild hemophilia may bleed excessively in response to injury or trauma. Female hemophilia carriers have varying degrees of activity factor. Some may be close to normal levels and show no bleeding tendencies, while others may have a reduction of less than 50% and may bleed more than women who are not carriers.

In severe hemophilia, episodes of bleeding usually begin within the first 2 years of life. Severe bleeding after circumcision in men is sometimes the first sign of the disease. Symptoms may appear later in those with mild or moderate illness. Hemorrhagic hemophilia can occur anywhere in the body. The common sites to bleed are the joints, the muscles and the digestive system. The specific locations and types of bleeding are discussed below.

Hemorrhoid (bleeding in the joints) is a characteristic of hemophilia. The knees and ankles are often affected. Bleeding causes swelling of the common spaces, great pain and, over time, can deform. Over time, joint destruction occurs and joint replacement surgeries may be required.
Bleeding in the muscle can occur with the formation of a hemangioma (compartment syndrome).
Bleeding can occur from the mouth or bleeding in the nose. Bleeding After dental procedures is common, bleeding from the gums can occur in young children when new teeth appear.
Bleeding from the digestive system can lead to blood in the stool.
Bleeding from the urinary tract can lead to blood in the urine (hematuria).
Intracranial bleeding (bleeding in the brain or skull) can cause symptoms such as nausea, vomiting and / or inactivity, and can cause death.
Increased bleeding after surgery or trauma is characteristic of hemophilia.

How is hemophilia diagnosed?

Most patients with hemophilia have a known family history of this condition. However, approximately one third of cases occur in the absence of a known family history. Most of these cases without a family history arise due to a spontaneous mutation in the affected gene. Other cases may be due to the damaged gene passing through a long line of female vectors.

If a family history of hemophilia is not known, a series of blood tests can determine which part or protein factor of the blood coagulation mechanism is defective if the individual has abnormal bleeding episodes.

Blood platelets (the necessary blood particles of coagulation), the bleeding time test, blood coagulation indicators, prothrombin time (bit) and activated thromboplastin time (ABT) should be measured. . In hemophilia A and hemophilia B there is usually a normal number of platelets, normal pieces and abt for long periods of time. Then, specific tests of blood coagulation factors can be performed to measure factor VII or factor IX levels and confirm the diagnosis.

Genetic tests to identify and characterize specific mutations responsible for hemophilia are also available in specialized laboratories.

Is it possible to know if you are the carrier of hemophilia?

Since men suffering from genetic mutations will have hemophilia, a man who has no condition can not be the carrier of the disease. A woman with a child with known hemophilia is called a carrier and no test is needed to make sure she is the carrier of hemophilia.

Women who do not know their pregnancy status can be evaluated either by analysis of coagulation factors or by ways of characterizing the DNA mutation. DNA detection methods are generally the most reliable.

Prenatal diagnosis is also possible with DNA-based tests performed on a sample obtained by amniocentesis or chorionic villus sampling. Most experts are seen and tested by consultants who specialize in genetically related diseases.


What are the treatments for hemophilia?


The basis of the treatment is the replacement of blood coagulation factors. The clotting factor concentrates can be purified from blood from human donors or manufactured in vitro using methods that do not use donor blood. This type of treatment is known as alternative therapy. The coagulation factor replacement therapy is performed by the implantation of an intravenous coagulation factor, very similar to transfusion. This type of treatment can be administered at home with the appropriate training and training.

Depending on the severity of the condition, an alternative treatment of the factor insufficiently coagulant can be performed according to needs (called dialysis therapy) or on a regular basis to prevent episodes of bleeding (known as prophylaxis).

People suffering from mild cases of hemophilia A are sometimes treated with drugs for dismopressin, also known as duff. This medication stimulates the release of substances from platelets that help form platelet components. Either slowly administered through the vein (IV) or, sometimes, in the form of a nasal spray.

It may be described as analgesic to relieve symptoms, but you should use analgesics other than aspirin or non-steroidal anti-inflammatory drugs (eg, naproxen, ibuprofen), because these types of drugs increase the ability of blood to clot. Paracetamol (telenol, etc.) is often given to relieve


An important complication of the treatment is the development of the so-called inhibitors of the coagulation factors. Antibodies (antibodies) are produced because the body sees a factor that focuses on treating patients to reduce or prevent bleeding, as a foreigner and activates an immune response in the patient to destroy foreign substances (Factor VIII or Factor IX) .


Factor VIII inhibitors are more common and occur in about one third of those with severe hemophilia A and about 1 in 50 people with mild or moderate hemophilia A. They develop normally in childhood in those with severe hemophilia A and then in life in lighter cases. Inhibitors destroy the factor VIII replacement factor plus any factor VIII in the body. This is a serious complication of the treatment because the concentrates are no longer effective in the treatment of this condition. The work of inhibitors to destroy the agent in the center concentrates different degrees of intensity between individuals, and can vary even over time in the same individual.

In about two thirds of cases, the inhibitors disappear on their own or with a treatment known as tolerance to immunotherapy (ET) or immunological tolerance (ITE). In cases of acute hemophilia A with persistent inhibitors, other factors such as activation of the prothrombin compound promoter or VIA regenerative agent are treated to help control bleeding.

The development of inhibitors for factor IX is much less common and occurs in approximately 1% of those with hemophilia B. However, this sensitivity reaction can cause very severe allergic reactions when factor IX is administered. Immune tolerance therapy to eliminate less successful inhibitors than with A. hemophilia.


Bloodborne infections, such as HIV, hepatitis B and C, were major complications in the treatment of hemophilia during the 1980s. This infection has been transmitted through concentrates of agents and other blood products used to treat hemophilia. The use of large blood donation complexes for the development of agent concentrates and the absence of specific tests for infectious agents contributed to the contamination of blood products used for the treatment of hemophilia. In 1985, approximately 90% of patients with severe hemophilia had HIV, and approximately half of all patients with hemophilia had HIV. Today, improved detection and manufacturing practices, including virus removal techniques, as well as the development of combined agents, have eliminated these catastrophic treatment complications.


Can hemophilia be prevented?

  Hemophilia is a hereditary disease that can not be prevented. Genetic counseling, identification of carriers through molecular genetic testing and prenatal diagnosis are available to help people understand the risk of having a child with hemophilia.


What are the predictions (prediction) of hemophilia?

 Before placing the agent concentrations, people with hemophilia had a significantly lower life expectancy. Life expectancy before the 1960s for severe hemophilia was limited by 11 years. Currently, the mortality rate (mortality) among men with hemophilia is twice as high as that of healthy men. As mentioned earlier, the increase in HIV infection and hepatitis associated with treatment during the 1980s led to a corresponding increase in mortality rates.

Currently, timely and appropriate treatment can significantly reduce the risk of life-threatening hemorrhagic attacks and long-term joint damage, but joint degradation remains a chronic complication of hemophilia.

What are the possible future treatments for hemophilia?

Several experiments and studies are underway to study the possibility of using gene therapy to replace the defective genes in hemophilia. So far, stable and sustainable production of human coagulation factors has not been achieved, but this is an area of ​​active research that promises a lot in the future.



Centers for Disease Control. Hemophilia.

eMedicine.com. Hemophilia A and B.
< http://emedicine.medscape.com/article/955590-overview>

eMedicine.com. Hemophilia.
<overview. http://emedicine.medscape.com/article/210104-overview>

eMedicine.com. Hemophilia C.


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