Thalassemia: Causes, Symptoms, Types & Tests

Thalassemia is an inherited blood disorder that leads to reduced or abnormal production of hemoglobin the protein in red blood cells responsible for carrying oxygen throughout the body. This results in anemia, fatigue, and other health complications. It is especially prevalent in people of Mediterranean, South Asian, Middle Eastern, and African descent. Advances in diagnosis and treatment have significantly improved the life expectancy and quality of life for patients, but managing thalassemia remains a lifelong commitment.

What is Thalassemia?

Thalassemia refers to a group of genetic disorders characterized by the body’s inability to produce sufficient amounts of hemoglobin. Hemoglobin consists of two types of protein chains: alpha (α) and beta (β). The disorder occurs when there is a defect in the genes that control the production of these chains. This defect causes the body to destroy red blood cells faster than they are produced, leading to anemia and related complications. Depending on which chain is affected, thalassemia is mainly classified into alpha thalassemia and beta thalassemia.

Causes of Thalassemia

Thalassemia is caused by mutations in the genes responsible for producing hemoglobin chains. Here’s how:

• Inherited disorder: Thalassemia is passed from parents to children through genes. To develop thalassemia, a child must inherit the defective gene(s) from one or both parents.
• Alpha thalassemia: Occurs when one or more of the four genes involved in making alpha globin chains are missing or mutated.
• Beta thalassemia: Results from mutations in one or both of the two genes responsible for beta globin chain production.

If a child inherits a mutated gene from only one parent, they become a carrier (thalassemia trait) and usually do not have symptoms or have only mild anemia. If they inherit defective genes from both parents, the disease is more severe.

Symptoms of Thalassemia

The severity and onset of symptoms depend on the type and form of thalassemia:

Common symptoms may include:

• Fatigue and weakness
• Pale or yellowish skin (jaundice)
• Slow growth in children
• Facial bone deformities, especially in the cheeks and forehead
• Dark urine
• Shortness of breath
• Enlarged spleen or liver

People with mild forms (thalassemia minor or trait) may have little or no symptoms, while those with severe types (thalassemia major) experience significant symptoms starting in infancy.

Types of Thalassemia

Thalassemia is divided into alpha and beta types, each with subtypes based on severity.

1. Alpha Thalassemia

• Involves missing or mutated alpha globin genes.
• Severity depends on how many of the four genes are affected:
  • Silent carrier: One gene missing; no symptoms.
  • Alpha thalassemia trait (minor): Two genes missing; mild anemia.
  • Hemoglobin H disease: Three genes missing; moderate to severe anemia, bone changes, enlarged spleen.
  • Hydrops fetalis: All four genes missing; usually leads to stillbirth or death shortly after birth.

2. Beta Thalassemia

• Involves mutations in the beta globin genes.
• Types include:
  • Thalassemia minor (trait): One gene affected; mild anemia.
  • Thalassemia intermedia: Both genes affected but less severe mutations; moderate anemia, sometimes requiring transfusions.
  • Thalassemia major (Cooley’s anemia): Both genes severely mutated; severe anemia, requires lifelong blood transfusions and medical care.

Tests Used to Diagnose Thalassemia

Accurate diagnosis is vital for proper management and includes:

• Complete Blood Count (CBC): Checks levels of hemoglobin and size of red blood cells. Microcytic anemia (small red blood cells) may be seen.
• Hemoglobin electrophoresis: Identifies different types of hemoglobin and detects abnormal forms.
• DNA analysis: Confirms mutations in the globin genes, useful for prenatal testing and family studies.
• Iron studies: Help distinguish thalassemia from iron deficiency anemia.
• Prenatal testing: Includes chorionic villus sampling (CVS) and amniocentesis to detect thalassemia in a fetus if both parents are carriers.

Early detection through screening, especially in high-risk populations, helps prevent severe cases.

Treatment and Management

Management depends on the type and severity:

• Mild thalassemia: Often does not need treatment. Regular check-ups and a healthy diet are advised.
• Moderate to severe thalassemia:
  • Regular blood transfusions: To maintain adequate hemoglobin levels.
  • Iron chelation therapy: Removes excess iron from the body, which accumulates due to repeated transfusions.
  • Folic acid supplements: Help support red blood cell production.
  • Bone marrow or stem cell transplant: The only potential cure, typically offered to younger patients with a suitable donor.
  • Splenectomy: Removal of an enlarged spleen if it worsens anemia.
  • Gene therapy: An emerging treatment showing promise in clinical trials.

Lifestyle considerations include avoiding infections, maintaining vaccinations, and regular monitoring of heart and liver function.

Conclusion

Thalassemia is a lifelong inherited blood disorder that can range from silent carrier status to life-threatening anemia requiring lifelong medical care. Advances in treatment have greatly improved the quality of life and life expectancy for those affected, but prevention through carrier screening and genetic counseling remains critical, especially in high-risk communities. By understanding the causes, symptoms, and available tests, individuals and families can take informed steps toward managing and preventing the severe impacts of thalassemia.

Frequently Asked Questions (FAQs)

What is thalassemia?
Thalassemia is an inherited blood disorder that affects hemoglobin production, leading to anemia.

Is thalassemia curable?
A bone marrow or stem cell transplant can potentially cure severe thalassemia, but it isn’t suitable for all patients.

How is thalassemia diagnosed?
Through blood tests like hemoglobin electrophoresis and genetic testing.

What are the types of thalassemia?
Alpha thalassemia and beta thalassemia, each with subtypes ranging from minor to major.

Can a person with thalassemia lead a normal life?
With proper treatment, many people live long and active lives, though severe cases need ongoing care.

What is thalassemia minor?
A carrier state where a person has mild anemia but usually no major symptoms.

Why do thalassemia patients need iron chelation?
To remove excess iron buildup from frequent blood transfusions, which can damage organs.

Can thalassemia be prevented?
Yes, through carrier screening and genetic counseling before or during pregnancy.

What are common complications?
Iron overload, bone deformities, delayed growth, and risk of infections.

Where is thalassemia most common?
It is more common in Mediterranean, Middle Eastern, South Asian, and African populations.