Thalassemia

Thalassemia

Thalassemia is a hereditary blood disorder characterized by the production of abnormal hemoglobin, the protein responsible for carrying oxygen in red blood cells. This condition results in the excessive destruction of red blood cells, leading to anemia.

Causes, Incidence, and Risk Factors

Thalassemia arises when there is a defect in the gene responsible for regulating the production of either alpha globin or beta globin proteins, the building blocks of hemoglobin.

There are two primary types of thalassemia:

• Alpha thalassemia: Caused by mutations or absence of genes related to alpha globin production.
• Beta thalassemia: Resulting from similar gene defects affecting beta globin production.

Alpha thalassemia is more prevalent among individuals from southeast Asia, the Middle East, China, and those of African descent. Beta thalassemia is common in people of Mediterranean origin, as well as in Chinese, other Asian, and African American populations.

Thalassemia encompasses various forms, each with multiple subtypes. The two main forms are:

• Thalassemia major
• Thalassemia minor

Thalassemia major manifests when the defective gene is inherited from both parents, while thalassemia minor occurs with inheritance from just one parent. Individuals with thalassemia minor usually don't display symptoms and are carriers of the disease.

Beta thalassemia major is also known as Cooley's anemia.

Risk factors for thalassemia include ethnic backgrounds such as Asian, Chinese, Mediterranean, or African American, as well as a family history of the disorder.

Symptoms

The severe form of alpha thalassemia major can lead to stillbirth, while infants with thalassemia major (Cooley's anemia) typically develop severe anemia within the first year of life.

Additional symptoms may include bone deformities in the face, fatigue, growth failure, shortness of breath, and jaundice.

Individuals with minor forms of alpha and beta thalassemia may exhibit small red blood cells without experiencing symptoms.

Signs and Tests

A physical examination may reveal an enlarged spleen.

Blood tests, including a complete blood count (CBC) and hemoglobin electrophoresis, can diagnose thalassemia by identifying abnormal red blood cell shapes and low hemoglobin levels.

Mutational analysis may be necessary to detect alpha thalassemia variants not visible through hemoglobin electrophoresis.

Treatment

Treatment for thalassemia major often involves regular blood transfusions and folate supplements.

Individuals receiving blood transfusions should avoid iron supplements to prevent iron overload, which can be harmful.

Chelation therapy may be necessary to remove excess iron from the body in those who require frequent blood transfusions.

In some cases, especially in children, a bone marrow transplant may offer a potential cure for the disease.