April 17, World Hemophilia Day
April 17, 2019, will mark the 28th World Hemophilia Day!
The World Federation of Hemophilia will focus on the importance of sharing knowledge. The bleeding disorders community is filled with the first-hand knowledge and experience needed to help increase awareness, as well as to improve access to care and treatmen
What is hemophilia?
Hemophilia is not one disease but rather one of a group of inherited bleeding disorders that cause abnormal or exaggerated bleeding and poor blood clotting. The term is most commonly used to refer to two specific conditions known as hemophilia A and hemophilia B, which will be the main subjects of this article. Hemophilia A and B are distinguished by the specific gene that is mutated (altered to become defective) and codes for a defective clotting factor (protein) in each disease. Rarely, hemophilia C (a deficiency of Factor XI) is encountered, but its effect on clotting is far less pronounced than A or B.
Hemophilia A and B are inherited in an X-linked recessive genetic pattern and are therefore much more common in males. This pattern of inheritance means that a given gene on the X chromosome expresses itself only when there is no normal gene present. For example, a boy has only one X chromosome, so a boy with hemophilia has the defective gene on his sole X chromosome (and so is said to be hemizygous for hemophilia). Hemophilia is the most common X-linked genetic disease.
Although it is much rarer, a girl can have hemophilia, but she would have to have the defective gene on both of her X chromosomes or have one hemophilia gene plus a lost or defective copy of the second X chromosome that should be carrying the normal genes. If a girl has one copy of the defective gene on one of her X chromosomes and a normal second X chromosome, she does not have hemophilia but is said to be heterozygous for hemophilia (a carrier). Her male children have a 50% chance of inheriting the one mutated X gene and thus have a 50% chance of inheriting hemophilia from their carrier mother.
Hemophilia A occurs in about 1 out of every 5000 live male births. Hemophilia A and B occurs in all racial groups. Hemophilia A is about four times more common than B. B occurs in about 1 out of 20- 30,000 live male births.
Hemophilia has been called the Royal Disease because Queen Victoria, Queen of England from 1837 to 1901, was a carrier. Her daughters passed the mutated gene on to members of the royal families of Germany, Spain, and Russia. Alexandra, Queen Victoria’s granddaughter, who became Tsarina of Russia in the early 20th century when she married Tsar Nicholas II, was a carrier. Their son, the Tsarevich Alexei, suffered from hemophilia.
Hemophilia symptoms include excessive bleeding and easy bruising. The severity of symptoms depends on how low the level of clotting factors is in the blood.
Bleeding can occur externally or internally.
Any wound, cut, bite, or dental injury can lead to excessive external bleeding.
Spontaneous nosebleeds are common.
There may be prolonged or continued bleeding after bleeding previously ceased.
Signs of excessive internal bleeding include blood in the urine or stools, and large, deep bruises.
Bleeding can also happen within joints, like knees and elbows, causing them to become swollen, hot to the touch, and painful to move.
A person with hemophilia may experience internal bleeding in the brain following a bump on the head.
Symptoms of brain bleeding can include headaches, vomiting, lethargy, behavioral changes, clumsiness, vision problems, paralysis, and seizures.
Hemophilia is treated with replacement therapy.
This involves giving or replacing the clotting factors that are too low or missing in a patient with the condition. Patients receive clotting factors by injection or intravenously.
Clotting factor treatments for replacement therapy can be derived from human blood, or they can be synthetically produced in a laboratory.
Synthetically produced factors are called recombinant clotting factors.
Recombinant clotting factors are now considered the treatment of choice because they further reduce the risk of transmitting infections that are carried in human blood.
Some patients will need regular replacement therapy in order to prevent bleeding. This is called prophylactic therapy.
This is typically recommended for people with the severe forms of Hemophilia A.
Others receive demand therapy, a treatment that is given only after bleeding begins and remains uncontrollable.
Complications from treatment of hemophilia are possible, such as developing antibodies to treatments and viral infections from human clotting factors.
Damage to joints, muscles, and other body parts can occur if treatment is delayed. Other treatments, for moderate forms of hemophilia A, include desmopressin, a man-made hormone that stimulates the release of stored factor VIII, and antifibrinolytic medicines that prevent clots from breaking down.
In 2019, the U.S. Food and Drug Administration (FDA) approved Rixubis, a purified protein created with recombinant DNA technology, for patients with hemophilia B.
Rixubis, a lab produced blood factor IX, aims to prevent and control excessive bleeding by replacing the clotting factor missing or in low levels in hemophilia B patients.
In the future, gene therapies may be available. People who wish to join a clinical trial can contact the National Heart Lung and Blood Institute (NHLBI).