Thalassemia

Reviewed by Jessica Muñoz, Jessica Muñoz is a registered nurse and educator with 20 years of experience in critical care emergency nursing, specializing in patient care, education, and evidence-based practice. She holds multiple certifications and serves as a Patient Safety Coordinator.

Thalassemia is an inherited blood disorder passed from parents to children through genes. It occurs when the body doesn’t produce enough hemoglobin, a crucial protein in red blood cells. With low hemoglobin levels, red blood cells function poorly and have a shortened lifespan, resulting in a deficiency of healthy red blood cells in the bloodstream.

Red blood cells carry oxygen to all body cells, which is essential for their proper function. Insufficient healthy red blood cells lead to inadequate oxygen delivery to tissues, causing patients to experience fatigue, weakness, or shortness of breath—a condition known as anemia. The severity of anemia can vary from mild to severe, with severe cases posing a risk of organ damage and even death.

Types of thalassemia

When examining various types of thalassemia, we can classify them into two main categories: based on the specific component of hemoglobin affected (typically either “alpha” or “beta”), or based on the severity of the condition. Hemoglobin, which is responsible for oxygen transport to the body’s cells, consists of two distinct parts: alpha and beta. When discussing “alpha” or “beta” thalassemia, we are referring to the deficient part of hemoglobin production. In cases where either the alpha or beta component is inadequately produced, there are insufficient building blocks to generate normal hemoglobin levels. “Alpha thalassemia” describes low alpha production, while “beta-thalassemia” denotes low beta production.

Alpha-thalassemia

There are four genes responsible for producing the hemoglobin chain. Inherited thalassemia occurs when a patient receives two of these genes from each parent.

When only one gene is mutated, there are typically no signs or symptoms of thalassemia, but the individual carries the disease and can transmit it to their offspring.

With two mutated genes, thalassemia symptoms are generally mild, and categorized as the alpha-thalassemia trait.

With three mutated genes, symptoms can range from mild to severe.

Inheriting four mutated genes is rare and often leads to stillbirth. Babies born with this condition usually pass away shortly after birth or require lifelong transfusion therapy. In rare cases, treatment may involve transfusions and a stem cell transplant.

Beta-thalassemia

The beta hemoglobin chain is produced by two genes, one inherited from each parent.

When one gene is mutated, mild signs and symptoms may appear, referred to as thalassemia minor or beta-thalassemia.

If both genes are mutated, symptoms can range from moderate to severe, known as thalassemia major or anemia.

Babies born with two defective beta hemoglobin genes are typically healthy at birth but may develop symptoms within the first two years of life. In addition, a moderate form called thalassemia intermedia can develop from two mutated genes.

Symptoms

Infants with beta-thalassemia major, also known as Cooley anemia, usually seem healthy at birth but develop severe anemia within their first year of life.

Additional signs and symptoms may include:

• Failure to thrive
• Facial bone deformities
• Fatigue
• Pale or yellowish skin
• Shortness of breath
• Dark urine
• Abdominal swelling

Individuals with the minor forms of alpha and beta-thalassemia may have small red blood cells, but they typically do not show symptoms.

Complications

The complications of mild to severe thalassemia may include:

1. Iron Overload: Thalassemia patients may accumulate excess iron in their bodies due to the disease itself or frequent blood transfusions. Elevated iron levels can damage the liver, heart, and endocrine system, impacting hormone production.
2. Infection: Individuals with thalassemia, particularly those who have undergone spleen removal surgery, are at a heightened risk of infection.

Specific complications associated with severe thalassemia include:

1. Bone Deformities: Thalassemia can cause bone marrow expansion, leading to widened bones and abnormal bone structure in the skull and face. Additionally, bone marrow expansion can render bones thin and fragile, increasing fracture risks.
2. Enlarged Spleen: Thalassemia-induced breakdown of a large number of red blood cells can enlarge the spleen, causing it to work harder than usual. This can exacerbate anemia and reduce the lifespan of transfused red blood cells. In severe cases, spleen removal surgery may be recommended.
3. Slowed Growth Rates: Anemia associated with thalassemia can impede a child’s growth and delay puberty.
4. Heart Problems: Severe thalassemia may result in congestive heart failure and abnormal heart rhythms.

Treatment

Common treatments for those with thalassemia major are blood transfusions and iron chelation.

Treatment options for thalassemia include:

1. Blood transfusion: This procedure involves injecting red blood cells into a vein to replenish healthy red blood cell and hemoglobin levels. Individuals with moderate or severe thalassemia typically undergo transfusions every four months, while those with beta-thalassemia major may require transfusions every two to four weeks. Occasional transfusions may also be necessary for hemoglobin H disease or beta-thalassemia intermedia in cases of infection.
2. Iron chelation therapy: Blood transfusions can lead to iron overload, which may damage other organs. Patients receiving frequent transfusions often require iron chelation therapy, administered in pill form, to remove excess iron from the body.
3. Nutritional supplements: Folic acid supplements are commonly prescribed to support healthy blood cell production. Monitoring levels of vitamin B12, another essential nutrient for blood cell formation, is crucial.
4. Bone marrow and stem cell transplant: This procedure, performed using stem cells from a compatible donor, is the only curative treatment for thalassemia. A compatible donor has similar human leukocyte antigens (HLA) to the recipient. Transplants from a sibling with compatible HLA markers offer the best chance of success, but suitable donors are often rare. Due to the high risks involved, bone marrow transplants are typically reserved for severe cases and are conducted in a hospital setting. Transplanted stem cells begin producing new, healthy blood cells within a month. However, this treatment is rarely recommended for individuals with mild or moderate thalassemia due to its associated risks.

Works cited

• What is Thalassemia? 2023. CDC.gov.
  https://www.cdc.gov/thalassemia/about/
• Thalassemias. 2022. My.Clevelandclinic.org.
  https://my.clevelandclinic.org/health/diseases/14508-thalassemias
• Thalassemia. 2022. Medlineplus.gov.
  https://medlineplus.gov/ency/article/000587.htm