Definition

Hemophilia is an inherited blood disorder where the blood clotting process is impaired, leading to prolonged bleeding after injury or surgery. Patients can experience spontaneous bleeding, which can be especially concerning if it occurs in organs or tissues and becomes life-threatening.

Blood contains several proteins, known as clotting factors, which work together with platelets to stop bleeding by forming clots. Individuals with hemophilia typically have low levels of clotting factor VIII or IX.

The severity of hemophilia varies depending on the level of clotting factor in the blood. The lower the clotting factor level, the greater the risk of bleeding, which can lead to serious health problems.

Hemophilia affects approximately 1 in every 5,000 male births and can occur in individuals of all racial and ethnic groups. It is predominantly a genetic or hereditary disease, although very rare cases may involve the development of hemophilia later in life.

Causes

There are several types of hemophilia, each determined by the levels of clotting factors in the blood:

• Hemophilia A: This is the most common type, caused by a deficiency in clotting factor VIII. Approximately 10 out of 100,000 people have hemophilia A.
• Hemophilia B: This type is caused by a deficiency in clotting factor IX. Approximately 3 out of 100,000 people have hemophilia B.
• Hemophilia C: This condition results from a deficiency in factor XI and is the rarest type, affecting 1 out of 100,000 people.

When an individual experiences bleeding, the body forms blood clots in the injured area to stop the bleeding. Several genes are involved in the formation of clotting factors. In inherited hemophilia, mutations or changes occur in the genes responsible for producing normal clotting factors.

These gene mutations can impair the function of clotting factors or result in their absence. They may also lead to the production of abnormal clotting factors or reduce the amount of clotting factors required by the body. The genes involved are located on the X chromosome. Males have one X chromosome and one Y chromosome (XY), while females have two X chromosomes (XX). The X chromosome carries many genes not present on the Y chromosome.

Genetic Mutation Heiring Process

Men have only one copy of most genes on the X chromosome, so they can have hemophilia if they inherit an X chromosome with a genetic mutation. Women with one affected X chromosome can carry the hemophilia trait for their offspring.

If a woman carries a genetic mutation on one of her X chromosomes and has a son, the son has a 50% chance of inheriting the X chromosome carrying the abnormal factor gene.

Similarly, if the same woman has a daughter, the daughter also has a 50% chance of inheriting the X chromosome and gene with the abnormal factor. However, the daughter is unlikely to experience symptoms because she will inherit a normal X chromosome from her father.

Cases of women suffering from hemophilia are much rarer. This can occur when one X chromosome is affected and the other X chromosome is lost or inactive.

Risk factor

The primary risk factor for hemophilia is having family members with the disorder. Males are much more likely to experience hemophilia than females.

While hemophilia is typically inherited within families, it's important to note that some families may not have a history of the disorder. In approximately one-third of cases, babies with hemophilia are the first in their family to have the clotting factor gene mutation.

Symptoms

Signs of hemophilia commonly include spontaneous bleeding or bleeding that lasts longer than normal. Bleeding can manifest in various ways, including:

• Joints often affecting the knees, elbows, and ankles, leading to swelling, pain, or tightness in the joints
• Skin, muscles, or soft tissue, resulting in unexplained bruises
• Mouth and gums, particularly after losing a tooth
• A baby's head following a difficult birth

Symptoms of bleeding may occur after an injury or medical procedure. Boys with hemophilia may experience prolonged bleeding after circumcision, while vaccination or injections can also trigger bleeding episodes. Nosebleeds can occur frequently without a clear cause and may be challenging to stop. Additionally, blood may be present in stool or urine.

Diagnosis

During pregnancy, the mother is typically asked about her pregnancy history, family medical history, and her own medical history, including any ongoing treatments. If there is a family history of hemophilia, special attention is given when a male newborn is born, and the baby is checked after birth.

To diagnose hemophilia, doctors perform specific blood tests to assess how blood clots in the child. These tests include:

• Complete blood count (CBC) to assess levels of blood cells.
• Prothrombin time (PT) test to measure how quickly blood clots.
• Activated Partial Thromboplastin Time (APTT) test to measure the time it takes for blood to clot in seconds.

If blood clotting is impaired, the doctor will perform coagulation factor tests, also known as factor assays, to determine the cause of the blood disorder. Decreased levels of factor VIII and factor IX are typically found in hemophilia. The levels of these clotting factors help the doctor determine the type and severity of hemophilia.

Management

Hemophilia is typically treated by replacing the missing clotting factor to facilitate proper blood clotting. This is achieved by administering clotting factor concentrates via infusion. These concentrates can be derived from human plasma donations or synthetic laboratory versions.

Generally, patients with severe hemophilia require repeated replacement therapy with clotting factor concentrates. In addition to replacement therapy, patients may receive antifibrinolytic medications, which help prevent blood clots from breaking down.

Complications

Complications of hemophilia commonly arise from untreated spontaneous bleeding and may include:

• Bleeding in the throat or neck, which can result in breathing difficulties.
• Bleeding in the joints leads to joint compression and severe pain.
• Bleeding in the head and brain can cause long-term disorders such as seizures and paralysis.
• Death may occur if bleeding cannot be controlled or if it affects vital organs such as the brain.

Prevention

Hemophilia cannot be prevented, but genetic testing can help individuals with hemophilia and their partners understand the likelihood of passing on the hemophilia gene to their children. If you have hemophilia and wish to have children, your doctor may recommend genetic testing to assess the risk of inheritance.

Additionally, genetic testing can be performed on children to determine whether they carry the hemophilia gene and whether they may pass it on to future generations.

When to see a doctor?

If you or your child experience spontaneous bleeding that does not stop even after initial treatment, seek medical help immediately.

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