What is Sickle Cell Disease?

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What is Sickle Cell Disease? Blog Image


The United Kingdom’s drug regulator recently approved the world's first gene therapy treatment for sickle cell disease and thalassemia.

About Sickle Cell Disease

  • It is an inherited blood disorder.
  • It is marked by flawed hemoglobin. 
  • Hemoglobin is the molecule in red blood cells (RBCs) that carries oxygen to the tissues of the body.
  • People with this disease have atypical hemoglobin molecules called hemoglobin S, which can distort RBCs into a sickle, or crescent, shape.
  • Sickle cell disease interferes with the delivery of oxygen to the tissues.
  • How does it affect blood flow?
    • Normally, RBCs are disc-shaped and flexible enough to move easily through the blood vessels.
    • In sickle cell disease, RBCs become crescent- or “sickle”-shaped due to a genetic mutation.
    • These sickled RBCs do not bend or move easily and can block blood flow to the rest of the body.
  • What causes it?
    • The cause of Sickle cell disease is a defective gene, called a sickle cell gene.
    • A person will be born with sickle cell disease only if two genes are inherited—one from the mother and one from the father.
  • Symptoms:
    • Early stage: Extreme tiredness or fussiness from anemia, painfully swollen hands and feet, and jaundice.
    • Later stage: Severe pain, anemia, organ damage, and infections.
  • Treatments:
    • A bone marrow transplant (stem cell transplant) can cure sickle cell disease.
    • However, there are treatments that can help relieve symptoms, lessen complications, and prolong life.
    • Gene therapy is also being explored as another potential cure. The UK recently became the first country to approve gene therapy treatment for sickle cell disease

Key Facts about Thalassemia

  • It is an inherited blood disorder caused when the body doesn’t make enough hemoglobin.
  • When there isn’t enough hemoglobin, the body’s RBCs don’t function properly, and they last shorter periods of time, so there are fewer healthy RBCs traveling in the bloodstream.
  • When there are not enough healthy RBCs, there is also not enough oxygen delivered to all the other cells of the body, which may cause a person to feel tired, weak, or short of breath. This is a condition called anemia.
  • People with thalassemia may have mild or severe anemia. Severe anemia can damage organs and lead to death.
  • Thalassemia is a treatable disorder that can be well-managed with blood transfusions and chelation therapy.

Q1) What is Gene Therapy?

Gene therapy is a technique that uses a gene(s) to treat, prevent or cure a disease or medical disorder. Often, gene therapy works by adding new copies of a gene that is broken, or by replacing a defective or missing gene in a patient’s cells with a healthy version of that gene. Both inherited genetic diseases (e.g., hemophilia and sickle cell disease) and acquired disorders (e.g., leukemia) have been treated with gene therapy.

Source: Britain approves world's first gene therapy Casgevy for sickle cell disease and thalassemia