What kind of genetic disorder is hemophilia

Hemophilia is a bleeding disorder that slows the blood clotting process. People with this condition experience prolonged bleeding or oozing following an injury, surgery, or having a tooth pulled. In severe cases of hemophilia, continuous bleeding occurs after minor trauma or even in the absence of injury spontaneous bleeding. Serious complications can result from bleeding into the joints, muscles, brain, or other internal organs. Milder forms of hemophilia do not necessarily involve spontaneous bleeding, and the condition may not become apparent until abnormal bleeding occurs following surgery or a serious injury.

The major types of this condition are hemophilia A also known as classic hemophilia or factor VIII deficiency and hemophilia B also known as Christmas disease or factor IX deficiency. Although the two types have very similar signs and symptoms, they are caused by mutations in different genes. People with an unusual form of hemophilia B, known as hemophilia B Leyden, experience episodes of excessive bleeding in childhood but have few bleeding problems after puberty.

The two major forms of hemophilia occur much more commonly in males than in females. Hemophilia A is the most common type of the condition; 1 in 4, to 1 in 5, males worldwide are born with this disorder. Hemophilia B occurs in approximately 1 in 20, newborn males worldwide. Changes in the F8 gene are responsible for hemophilia A, while mutations in the F9 gene cause hemophilia B. A related protein, coagulation factor IX, is produced from the F9 gene.

Coagulation factors are proteins that work together in the blood clotting process. After an injury, blood clots protect the body by sealing off damaged blood vessels and preventing excessive blood loss. Mutations in the F8 or F9 gene lead to the production of an abnormal version of coagulation factor VIII or coagulation factor IX, or reduce the amount of one of these proteins.

The altered or missing protein cannot participate effectively in the blood clotting process. As a result, blood clots cannot form properly in response to injury.

These problems with blood clotting lead to continuous bleeding that can be difficult to control. The mutations that cause severe hemophilia almost completely eliminate the activity of coagulation factor VIII or coagulation factor IX.

A baby girl will inherit an X chromosome with a dominant gene for normal blood clotting from her father. So the daughter will not have hemophilia. A daughter will get either her mother's X chromosome with the hemophilia gene or her mother's X chromosome with the normal gene for clotting. If she gets the X chromosome with the hemophilia gene she will be a carrier. A woman who is a carrier has:.

Father with normal gene; mother a carrier. If the boy gets his mother's X chromosome with the hemophilia gene he will have hemophilia. The girl also gets an X chromosome from her mother.

If she gets the normal X chromosome, the girl will be a carrier. If she gets the X chromosome with the hemophilia gene, she will have hemophilia. A man who has hemophilia and a woman who is a carrier have:. This is shown in Figure It is very rare for a man with hemophilia and a woman who is a carrier to get together. That is why there have been only a few girls born with hemophilia. Father with hemophilia; mother a carrier.

In some families, there is no known family history of hemophilia. The hemophilia gene seems to appear from nowhere and the family is shocked and confused. There are several reasons this could happen. First, the family may not know about or may have forgotten ancestors with hemophilia.

Second, the gene for hemophilia may have been passed down by carrier females without anyone knowing. For several generations, the women may have had no boy children or by chance had only normal boys. No one would have known about the hemophilia gene. Third, hemophilia may appear in families with no history of it if the normal blood clotting gene suddenly becomes messed up a spontaneous genetic mutation.

Normally, genes are exactly copied generation after generation. Sometimes, though, a gene may become faulty. It may give different or wrong directions to the body. This change in the gene is called a mutation. The effects of the faulty gene may be noticed right away. Or they might not be seen until the gene is passed on to a baby. So the change in the gene may have happened in the parent or in the baby. The change in the gene can be caused by something in the environment.

It also seems to happen without any clear cause. Since they are nature's way of bringing about change, not all gene mutations are harmful. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional. Treatment Treatment. People with inherited hemophilia A require life-long care, preferably through a specialized hemophilia treatment center. The National Hemophilia Foundation has links to management and treatment guidelines.

There is no cure for hemophilia A, but current treatments can prevent many of the symptoms of hemophilia A [4]. Treatment may include medications and replacing the missing clotting factor replacement therapy. This type of replacement therapy is done by slowly injecting or dripping concentrated factor VIII into a vein intravenous infusion. The type and frequency of treatment often depends on the severity of the disorder in each person.

Drugs known as antifibrinolytics , which slow the breakdown of clotting factors in the blood, can also be used to treat a mild form of the disorder. This is referred to as prophylactic or preventative therapy. These factor VIII infusions may be done as often as necessary depending on the severity.

This is especially important for people with severe disease because the infusion works the best within one hour of a bleeding episode. In general, prompt treatment is important because it reduces pain and damage to the joints, muscles, or other affected tissues or organs. Antihemophilic factor recombinant , Fc fusion protein Brand name: Eloctate - Manufactured by Bioverativ, a Sanofi Company FDA-approved indication: November , antihemophilic factor recombinant , Fc fusion protein Eloctate was approved for the treatment of adults and children with Hemophilia A congenital Factor VIII deficiency for control and prevention of bleeding episodes, perioperative management, and routine prophylaxis to prevent or reduce the frequency of bleeding episodes.

National Library of Medicine Drug Information Portal Emicizumab-kxwh Brand name: Hemlibra - Manufactured by Genentech FDA-approved indication: October , emicizumab-kxwh Hemilibra received expanded approval for the routine prophylaxis to prevent or reduce the frequency of bleeding episodes in adult and pediatric patients ages newborn and older with hemophilia A congenital factor VIII deficiency without factor VIII inhibitors.

In November , it was approved for routine prophylaxis to prevent or reduce the frequency of bleeding episodes in adult and pediatric patients with hemophilia A congenital factor VIII deficiency with factor VIII inhibitors. July , NovoSeven RT was approved for the treatment of bleeding episodes and peri-operative management in adults and children with Glanzmann's thrombasthenia with refractoriness to platelet transfusions, with or without antibodies to platelets.

Prognosis Prognosis. Hemophilia A can be mild, moderate, or severe, depending on how much clotting factor VIII is in a person's blood. Life expectancy may depend on the response to treatment and the presence of other health conditions.

Life-threatening complications of hemophilia A include bleeding within the skull intracranial hemorrhage and bleeding into the soft tissue around important organs. Chronic, debilitating joint disease may also develop. Statistics Statistics. This disorder affects males more than females, and occurs equally in all races and ethnic groups. Do you have updated information on this disease? Find a Specialist Find a Specialist. Healthcare Resources To find a medical professional who specializes in genetics, you can ask your doctor for a referral or you can search for one yourself.

You can also learn more about genetic consultations from MedlinePlus Genetics. Related Diseases Related Diseases. Conditions with similar signs and symptoms from Orphanet. The differential diagnosis should include von Willebrand disease see this term and other coagulation anomalies leading to prolonged blood coagulation times.

Visit the Orphanet disease page for more information. Research Research. Clinical Research Resources ClinicalTrials. Click on the link to go to ClinicalTrials.

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Learn More Learn More. MedlinePlus was designed by the National Library of Medicine to help you research your health questions, and it provides more information about this topic. This website is maintained by the National Library of Medicine. The Merck Manuals Online Medical Library provides information on this condition for patients and caregivers. NHLBI is part of the National Institutes of Health and supports research, training, and education for the prevention and treatment of heart, lung, and blood diseases.

NHGRI is part of the National Institutes of Health and supports research on the structure and function of the human genome and its role in health and disease. NORD is a patient advocacy organization for individuals with rare diseases and the organizations that serve them. In-Depth Information GeneReviews provides current, expert-authored, peer-reviewed, full-text articles describing the application of genetic testing to the diagnosis, management, and genetic counseling of patients with specific inherited conditions.

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