Dhaka,  Sunday
14 July 2024

Thalassemia: Genetic Disease

Published: 22:27, 9 July 2024

Update: 13:46, 10 July 2024

Thalassemia: Genetic Disease

Photo : Collected

A thalassemia is a group of inherited blood disorders characterized by the body's inability to produce enough haemoglobin, the protein in red blood cells that carries oxygen. This condition leads to the destruction of a large number of red blood cells, which causes anaemia. The severity of thalassemia can vary widely, from mild anaemia to severe cases that require regular blood transfusions.

History of Thalassemia 

Thalassemia was first described in 1925 by Thomas Cooley. He was an American paediatrician and haematologist. Then 1938 Thalassemia was recognised as a genetic disease. In 1948, scientists discovered that Thalassemia was caused by abnormal haemoglobin. But in 1964, The Thalassemic mutation was discovered to protect against malaria. 

 Types of Thalassemia

Thalassemia is primarily classified into two major types based on which part of the haemoglobin molecule is affected:

 1. Alpha Thalassemia

Alpha thalassemia occurs when one or more of the four genes needed to make alpha-globin are missing or mutated. The severity of alpha thalassemia depends on how many of these genes are affected:

  • Silent Carrier State: One missing or altered gene. Usually, no symptoms.
  • Alpha Thalassemia Trait (Minor): Two missing or altered genes. Mild anaemia.
  • Haemoglobin H Disease: Three missing or altered genes. Moderate to severe anaemia, splenomegaly, and skeletal abnormalities.
  • Alpha Thalassemia Major (Hydrops Fetalis): All four genes are missing or altered. This condition is usually fatal before or shortly after birth.

 2. Beta Thalassemia

Beta thalassemia occurs when one or both of the two genes needed to make beta-globin are mutated. The severity depends on whether one or both genes are affected:

Beta Thalassemia Minor (Trait): One mutated gene. Mild anaemia, often asymptomatic.

Beta Thalassemia Intermedia: Two mutated genes, but less severe mutations. Moderate anaemia, with variable severity.

Beta Thalassemia Major (Cooley's Anemia): Two severely mutated genes. Severe anaemia, requiring regular blood transfusions and medical treatment.


Symptoms of thalassemia can vary depending on the type and severity of the disorder but often include:

  •  Fatigue and weakness
  • Pale or yellowish skin
  •  Facial bone deformities
  • Slow growth and development in children
  • Enlarged spleen and liver
  • Dark urine


Thalassemia is typically diagnosed through blood tests, including:

Complete Blood Count (CBC): Measures the overall health and number of blood cells.

Hemoglobin Electrophoresis: Identifies abnormal forms of haemoglobin.

DNA Testing: Confirms genetic mutations responsible for thalassemia.


The treatment for thalassemia varies depending on its severity:

Mild Thalassemia (Trait): Often requires no treatment, though regular monitoring is essential.

Moderate to Severe Thalassemia:

Blood Transfusions: Regular transfusions to maintain normal haemoglobin levels.

Iron Chelation Therapy: To remove excess iron from the body due to frequent blood transfusions.

Folic Acid Supplements: To support red blood cell production.

Bone Marrow or Stem Cell Transplant: The only potential cure, replacing defective bone marrow with healthy marrow from a donor.

Gene Therapy: An emerging treatment, still under research, aims to correct the genetic defects causing thalassemia.

Managing thalassemia involves regular medical care, a healthy diet, and avoiding infections. Patients often work closely with a healthcare team, including haematologists, to manage the condition and improve their quality of life. Genetic counselling is also recommended for individuals with a family history of thalassemia who are planning to have children.

The writer is a student of UNIVERSAL MEDICAL COLLEGE