Hemophilia is an inherited bleeding disorder in which one of the “proteins needed for blood clotting,” called clotting factors, is missing or does not work properly. The result is that the blood has difficulty clotting and the person experiences prolonged or spontaneous bleeding.
The two most common types of hemophilia are:
• Hemophilia I (A): due to a deficiency or defect of factor eight (8)
• Hemophilia (B): due to a deficiency or defect of factor nine (9); sometimes called “Christmas disease”
Both types are seen in all races and ethnicities and occur more often in men, but women who carry the disease gene can also have bleeding symptoms.
Hemophilia A
In hemophilia A, the amount of factor VIII in the blood is lower than normal, or the factor that is made does not work properly. This factor is one of the main proteins in the clotting pathway.
• Hemophilia A is the most common type of hemophilia.
• Most cases are passed from parents to children, but in about one-third of patients, the disease occurs due to a new gene mutation and there is no known family history.
Hemophilia B
In hemophilia B, factor IX is low or does not function properly. Like factor VIII, it is essential for blood clotting.
• Hemophilia B is less common than hemophilia A.
• Like hemophilia A, the disease is usually hereditary, but in some patients it occurs due to a new mutation in the gene.
Inheritance of hemophilia A and B
Both types of hemophilia A and B are X-linked and inherited as recessive:
• Women have two X chromosomes (XX) and men have one X and one Y (XY).
• The hemophilia gene is located on the X chromosome.
If the mother is a carrier of the hemophilia gene
There are four possibilities in every pregnancy:
- Healthy girl (non-pregnant)
- Girl carrying the hemophilia gene
- Boy without hemophilia
- Boy with hemophilia
A father with hemophilia passes the defective gene to all of his daughters (the daughters become carriers) but not to his sons, because the son receives a Y chromosome from the father, not an X.
A significant proportion of pregnant women have factor VIII or lower levels and may experience abnormal bleeding, such as heavy menstruation, easy bruising, or bleeding after dental procedures and surgery.
Hemophilia severity
The severity of hemophilia A and B is defined by the level of factor in the blood:
• Severe hemophilia
• Factor level less than 1 percent
• Spontaneous bleeding, especially into joints and muscles, even without obvious trauma
• Moderate hemophilia
• Factor level about 1 to 5 percent
• Bleeding after minor trauma or surgery, sometimes spontaneous bleeding
• Mild hemophilia
• Factor level about 6 to 40 percent
• Bleeding is usually seen only after surgery, tooth extraction, or serious trauma
• May not be diagnosed until adulthood
Symptoms of hemophilia A and B
People with hemophilia take longer to stop bleeding than healthy people. Bleeding can occur:
• Internally: inside joints (especially knees, ankles, and elbows), muscles, and internal organs
• Externally: after scrapes, cuts, tooth extractions, or medical procedures.
Common symptoms:
• Prolonged bleeding after injections, surgery, or tooth extraction
• Large, frequent bruises
• Joint bleeding (pain, swelling, warmth, and limited joint movement)
• Muscle bleeding, with pain, swelling, and limited movement
• In newborns, prolonged bleeding after circumcision or intramuscular injections
• In pregnant women: very heavy and prolonged menstruation, bleeding after childbirth or surgery
Diagnosis of hemophilia
Several types of tests are used to diagnose hemophilia:
- Basic coagulation tests such as prothrombin time (PT) and partial thromboplastin time (APTT)
- Factor specific test to measure factor VIII and IX levels and determine the type and severity of hemophilia
- If needed, genetic testing to identify the type of mutation and to screen family members, especially women of childbearing age.
In families with a history of hemophilia, it is recommended that:
• Infant boys be screened for factor levels in the first months of life.
• Female family members (sisters, cousins, etc.) be screened for factor levels at an appropriate age and, if possible, genetically, especially before marriage and pregnancy.
Hemophilia treatment
The basis of treatment for both types of hemophilia is the injection of replacement clotting factor:
• In hemophilia A: injection of factor VIII concentrate and, in some patients, the use of new drugs that enhance the coagulation process through other mechanisms.
• In hemophilia B: Injection of factor IX concentrate (plasma-derived or manufactured using modern laboratory methods) and new products with longer shelf life in the blood.
General treatment methods
- Treatment during bleeding: factor injection at the time of bleeding
• Preventive treatment: regular factor injection to prevent bleeding, especially in children and patients with severe hemophilia, to prevent joint destruction
• Use of auxiliary drugs such as anti-clotting drugs, simple methods of caring for the bleeding limb (rest, ice, keeping the limb elevated, etc.) according to the doctor’s opinion
The choice of product type and injection schedule is based on the patient’s age, severity of the disease, lifestyle, presence or absence of inhibitors, and the facilities of each country.
Living with hemophilia
With proper diagnosis, appropriate treatment, and regular follow-up, children and adults with hemophilia A and B can live active and productive lives. Key points:
• Regular follow-up at a comprehensive hemophilia treatment center and ongoing communication with a hematologist
• Family education for early detection of bleeding and timely factor infusion
• Attention to joint health, appropriate physiotherapy, and controlled physical activity
• Oral and dental health care and coordination with a dentist familiar with hemophilia
• Genetic counseling for families, especially pregnant women or those planning to become pregnant
• Psychological and social support for the patient and family
If you or a family member has prolonged bleeding, frequent bruising, or a family history of hemophilia, be sure to seek medical attention and counseling.