Reviewed By : Dr. Anjali D.
Following are common questions about Hemophilia:
- What is Hemophilia?
- What are the types of Hemophilia?
- Who are the people affected by this disorder?
- What are the causes of hemophilia?
- Can hemophilia be treated?
- Can girls have hemophilia?
- What are the symptoms of hemophilia?
- What are the features of hemophilia?
- What is the main cause of hemophilia?
- What are the side-effects of hemophilia?
- How can hemophilia be diagnosed?
- What are the screening tests for hemophilia?
- What are the lab values of tests for hemophilia?
- What are the prenatal tests for hemophilia?
- How does a woman become a carrier of hemophilia?
- What are the treatment methods of hemophilia?
- What are the ways to prevent hemophilia?
- What are the complications of hemophilia?
What is Hemophilia?
- Hemophilia is a rare group of inherited blood disorders where blood does not clot normally
- Disorder is mainly due to defects in,
- Blood vessels
- Coagulation mechanism
- Blood platelets
- A person afflicted with this condition can bleed spontaneously or longer, than a healthy person after injury or surgery
- Internal bleeding can also occur, that can damage organs and tissues. This condition can be life-threatening
- The blood coagulation mechanism changes blood from liquid to a solid, involving several clotting factors
- Fibrin is generated by the body and activated. Together with a platelet plug, it helps to stop bleeding.
- Coagulation factors are missing or deficient when blood does not clot properly
- Hemophilia A or B patients have genetic defects which give rise to deficiency in one of the blood clotting factors
- Hemophilia is rarely an “acquired” disorder
- “Acquired” means that the disorder was developed during a person's lifetime
- Mainly it happens when the body forms antibodies that attack the clotting factors in the bloodstream
- The antibodies may prevent the clotting factor from working
What are the types of Hemophilia?
- The two most common types of hemophilia are hemophilia A and hemophilia B
- Hemophilia A accounts for a majority of cases
- Hemophilia A is caused by insufficient clotting factor VIII
- Hemophilia B is the result of deficiency in clotting factor IX
- Symptoms are similar for both cases, but they have different clotting factors and slightly different treatments
- A third and unusual type of hemophilia also exists, known as Hemophilia C. It is caused by insufficient clotting factor XI.
- A rare form of hemophilia, also known as acquired hemophilia, is another type of this disorder. It is caused by the immune system, attacking clotting factors of blood.
Who are the people affected by this disorder?
- Most hemophilia patients are males, due to the way this condition is inherited
- It is estimated that one boy in 5000 will be born with hemophilia A. Whereas, one boy in every 30,000 will be born with hemophilia B.
- Women with the hemophilia gene can experience problems due to bleeding, such as, heavy periods
- A girl can be born with hemophilia when both parents have the hemophilia gene
- Tests can be performed before, during and after pregnancy, to find out whether the child has this disorder
- If there is no family history for hemophilia, it can be diagnosed when symptoms appear during childhood
What are the causes of hemophilia?
- Hemophilia is a genetic disorder caused due to mutation within the genes for coagulation factors VIII or IX
- In 70% of cases, hemophilia is inherited from a parent. Whereas for the rest of the cases, family history may be absent or may not be apparent.
- In cases where the disorder is acquired, the condition may be caused by a spontaneous genetic mutation at the time of fertilization
- The gene causing hemophilia usually contains information for the body to make clotting factors
- The gene is present in the X chromosome which is referred to as the sex chromosome
- A person's gender is determined by the pairing of two sex chromosomes (X and Y) inherited from their parents
- Males have XY pairing while females have XX pairing. One chromosome is supplied by the father and one from the mother. Fathers can provide either X or Y of the pair, whereas mothers give only X chromosomes.
- Men with hemophilia can transmit the Y Chromosome to their sons and the altered X chromosome to their daughters
- Sons are not affected by the altered gene, whereas daughters become carriers because they carry the modified gene (also known as obligate carriers)
Women carriers have one altered gene from their father and one properly functioning gene from their mother
- If a male child inherits his mother's unaltered gene, he will not have hemophilia
- The male child will have hemophilia, in case he inherits his mother's affected X chromosome
- If a female child inherits her mother's modified gene then she will be a carrier. There is a 50% chance that a female carrier's son (XY) will have hemophilia
- Female carriers of Hemophilia:
- A female carrier can pass on the gene for hemophilia to her children, if she is a carrier. Normally, such a person does not experience any symptoms.
- A woman is an obligate carrier of hemophilia, when one of the following conditions apply:
- She is the biological daughter of a man who has hemophilia
- She is the biological mother of more than one son with hemophilia
- She is the biological mother of at least one son with hemophilia and has one blood relative with the disorder
Though this condition is commonly found in males because it is an X chromosome linked disorder, sometimes it can cause bleeding symptoms in females too. Some significant cases are:
- Symptomatic carriers: Female carriers can have low (below 50%) levels of either FVIII or FIX and experience bleeding symptoms. Female carriers who exhibit bleeding symptoms are called symptomatic carriers.
- Daughters of a man with hemophilia and a mother who is a carrier: The daughter then inherits an altered X chromosome from each parent and so, will have hemophilia.
- Turner's syndrome: A rare chromosomal condition, in which females possess only one set of X chromosome. If these girls inherit the affected gene, they will suffer from this disease.
Can hemophilia be treated?
Hemophilia can be treated with replacement therapy and anti fibrinolytic medication.
Can girls have hemophilia?
Hemophilia is more common in males. However, girls can develop hemophilia if she inherits the altered gene from her father, as well as her mother. Thus, it is possible, but only in rare cases (refer question 4)
What are the symptoms of hemophilia?
The crucial signs and symptoms of hemophilia include excessive bleeding and easy bruising.
- The extent of bleeding depends on severity of hemophilia
- Children who have mild hemophilia may not have apparent signs of this disorder. However, during a dental procedure or an accident, there may be excessive bleeding.
Circumcision in males may also lead to heavy bleeding.
- Bleeding can be internal, as well as external
- Signs of external bleeding are:
- Bleeding due to a cut in the mouth or bite, or caused by loss of a tooth
- Nosebleeds for no apparent reason
- Heavy bleeding for a small cut
- Bleeding that again starts after stopping for a short time
- Signs of internal bleeding are:
- Blood in urine (due to bleeding in kidneys or bladder)
- Blood in stool (due to bleeding in stomach or intestines)
- Large bruises (bleeding into large muscles of the body)
- Bleeding in the Joints
- Bleeding in knees, elbows and joints is a usual form of hemophilia. This can occur without any obvious injury.
- Internal bleeding in joints is not visible, nor does it cause any acute pain. There may be tightness in joints which can become swollen, painful to bend and hot to touch
- As bleeding continues, so does the swelling. Finally, movement in the joint is lost temporarily. There may be acute pain and if it is not treated immediately, it can cause further damage to the joint.
- Bleeding in the Brain
- The most severe effect due to hemophilia is internal bleeding in the brain
- Even a minor bump to the head or a serious injury, can lead to internal bleeding
- Signs and symptoms of bleeding in the brain can include:
- Painful and a lasting headache, neck pain or stiffness
- Repeated vomiting
- Sleepiness or behavioral changes
- Weakness in limbs or difficulty walking
- Double vision
- Seizures or convulsions
- Soft Tissue Bleeding
- Bleeding in muscular tissues is known as soft tissue bleeding
- Bleeding in large muscle groups such as the hip flexors, can lead to severe anemia and unbalanced blood pressure
- Bleeding in the forearm or lower extremity can cause compartment syndrome
- Patients with compartment syndrome require certain immediate treatment to control bleeding
- Procedures to relieve pressure on nerves and blood vessel should be used for patients with this syndrome
What are the features of hemophilia?
- Hemophilia is a bleeding disorder that slows down the blood clotting process
- People with hemophilia bleed for a lot longer after an injury or surgery
- Severe hemophilia patients bleed spontaneously into joints and muscles
- Hemophilia is more common in males than females
What is the main cause of hemophilia?
Mostly hemophilia emerges as a genetic disorder, which means that the genetic makeup of a person determines whether the person has hemophilia or not. The condition is mainly caused by a defect in the clotting factor gene that lies on the X chromosome.
What are the side-effects of hemophilia?
Emergency symptoms of hemophilia are:
- Sudden pain, swelling and warmth in large joints, such as
- Severe bleeding from a minor injury
- Double vision
- Neck pain
How can hemophilia be diagnosed?
Hemophilia can be diagnosed before, during or after birth, if there's a family history of the disorder
- If there's no family history of hemophilia, it is possible to diagnose only when the child begins to walk or crawl. Bleeding in joints and easy bruising of the child may be a sign of this disorder.
- Mild hemophilia may be found later on, usually after injury or a dental or surgical procedure
- Tests before pregnancy:
- Genetic testing is available to determine the probability of passing the condition, to a child
- This involves testing a sample of a patient's tissues or blood to look for signs of genetic mutation that can give rise to hemophilia
- Tests during pregnancy:
- If a person has a family history of hemophilia and is pregnant, then tests for the altered gene need to be performed. These include:
- Chorionic villus sampling (CVS)- A small sample of placenta is taken from the womb and tested for the modified gene, normally during 11th to 14th week of pregnancy.
- Amniocentesis- A sample of amniotic fluid is extracted for testing, usually during 15th to 20th week of pregnancy
- There remains a slight risk of miscarriages or premature labor due to these procedures. Therefore, a person must fully discuss the risks involved with a doctor, before carrying out these tests.
- Tests after birth:
- If hemophilia is suspected after the child is born, a blood test will be able to confirm the diagnosis
- Blood from the umbilical cord, can be tested if there is a family history of hemophilia
- A blood test can be used to verify if the child has hemophilia A or B and how severe it is
What are the screening tests for hemophilia?
Screening tests are blood tests that show if blood is clotting properly. The various types of screening tests are:
- Complete Blood Count (CBC):
- CBC is used to find the following factors:
- Amount of hemoglobin (red pigment inside blood cells carrying oxygen)
- Size of red blood cells (RBCs)
- Number of RBCs
- Number of various types of white blood cells (WBCs)
- A person with hemophilia has normal CBC. However in cases when a person suffers excessive bleeding for a long time, the count for red blood cell or hemoglobin is low.
- Activated Partial Thromboplastin Time (APTT) Test:
- APTT test is used to calculate, how long it takes for blood to clot
- Factors VIII, IX, XI and XII can be measured with this test
- If clotting factors are very low, it takes longer than usual for blood to clot
- The results of this test show a longer clotting time for people with hemophilia A and B
- Fibrinogen Test
- Doctors use this test to assess the ability of a patient to form blood clots
- Fibrinogen test is ordered if a patient has an abnormal APTT or PT test result
- Fibrinogen is also known as clotting factor I
- Clotting factor tests, also called as factor assays are used to diagnose hemophilia
- The type of hemophilia and its severity can be evaluated by this test, which can help in constructing an effective treatment plan
What are the lab values of tests for hemophilia?
Levels of Factor VIII or IX in the blood:
- Severe hemophilia- less than 1% of normal
- Moderate hemophilia- 1 to 5% of normal
- Mild hemophilia- 5 to 30% of normal
What are the prenatal tests for hemophilia?
Conclusive diagnosis of hemophilia, before a child is born can be done with invasive procedures like amniocentesis or chorionic villus sampling.
How does a woman become a carrier of hemophilia?
A father can give half of his sex chromosomes to a child. So either it is X or it is Y chromosome. If the child inherits the Y chromosome it will be a boy and if X it will be a girl. If the boy inherits an altered X chromosome from the mother then he will hemophilia. Thus the mother is a carrier of the disorder as she herself does not suffer from the condition, but can pass on the hemophilia gene to her children.
What are the treatment methods of hemophilia?
What are the ways to prevent hemophilia?
Hemophilia cannot be cured, but patients who start prophylaxis by the age of three, show better musculoskeletal result and lesser joint bleeds. People with hemophilia should:
- Avoid aspirin and non steroidal anti-inflammatory drugs (NSAIDs)
- Avoid blood thinning medication like heparin, warfarin (Coumadin), clopidogrel (Plavix) and prasugrel (efficient)
- Get Hepatitis B vaccine
- Take factors VIII or IX regularly, to prevent bleeding and joint damage
- Avoid circumcising male infants of women who have a family history of hemophilia, until the baby has been tested
- Carrying the information that a person suffers from hemophilia, at all times
- In-vitro fertilization may allow implantation of embryos which don't have the hemophilia gene
- Perform regular low-impact exercise, like swimming, bicycle riding and walking
- Practice good dental hygiene to prevent tooth extraction which might lead to bleeding
- Protect children with this disorder from injuries with kneepads, elbow pads and helmets
What are the complications of hemophilia?
- Hemophilia can lead to a variety of difficulties that require additional treatment
- Some people may develop specific antibodies in the immune system known as inhibitors
- The immune system treats clotting factors like foreign objects (like germs) and tries to block its effects
- Poorly-controlled hemophilia can lead to joint damage. However, it is becoming less common with modern treatments.
- Inhibitors can reduce the effectivity of medication used to treat hemophilia
- 20 to 30% of people having treatment for severe hemophilia A may develop inhibitors
- Mild or moderate hemophilia A are less likely to develop inhibitors
- Inhibitors are usually generated during the first year of treatment, but it can happen any time
- Hemophilia B patients rarely develop inhibitors, but if it does, then the person can experience life-threatening anaphylaxis during treatment
- People with mild to moderate hemophilia A generally require a test after receiving intensive treatment, or annually with normal treatment
- Inhibitors are temporary problems, but if it is constant, then there are ways of managing it
- Immune tolerance induction (ITI) for hemophilia A:
- People with persistent inhibitors are advised to develop a treatment program called as immune tolerance induction (ITI). These are performed at specialist hemophilia care centers.
- Daily injections of octocog alfa help to stop inhibitor production
- ITI is carried out on a long-term basis with treatment lasting from 6 to 24 months
- Mild to moderate hemophilia A is treated with bypass surgery or immunosuppressants
- Immune tolerance induction (ITI) for hemophilia B:
- ITI can treat persistent inhibitors in hemophilia B by receiving daily injections of nonacog alfa
- ITI is less successful at treating inhibitors in hemophilia B than hemophilia A
- Joint damage:
- Continuous joint bleeds can damage cartilage (the soft spongy tissue in joints that function as a shock absorber) as well as synovium (a thin layer of tissue that lines the inner surface of a joint)
- If a joint gets damaged, then it is further susceptible to internal bleeding
- Joint damage is more common with older people with severe hemophilia as preventive treatment wasn't available in the past. Nowadays, children with hemophilia don't have to suffer joint damage due to modern treatments.
- If joint is damaged beyond repair, then the whole joint can be replaced by procedures like hip replacement or knee replacement surgery