Why in the News?

The UK's medicines regulator has granted approval for the world's first gene therapy treatment for sickle cell disease.

What is Sickle Cell Disease?

• Sickle cell disease (SCD) is a blood disorder that is passed through the genes and results in abnormal hemoglobin.
• (Hemoglobin is a part of the red blood cells that carry oxygen through the body.)
• People with SCD have red blood cells that sickle or change shape when exposed to low oxygen levels in the cell.
• These sickled cells also become stiff and sticky compared to normal red blood cells.
• They can block blood flow, leading to tissue damage and pain.
• Over time, these blockages can lead to organ dysfunction and result in other serious medical complications.

Sickle Cell Disease Types

• There are several different forms of sickle cell disease, and it is different for each person.
• Hemoglobin SS, also known as sickle cell anemia
• Hemoglobin SC disease
• Hemoglobin sickle beta-thalassemia
• The most common and usually the most severe form is sickle cell anemia.
• The SCD type affects the severity and frequency of complications.
• The type of SCD also impacts the timing of complications.
• Some people have symptoms at a very young age while others will not show symptoms until adulthood.

Sickle Cell Disease Symptoms

• Anemia: Sickled blood cells are less able to carry oxygen, leading to anemia.
• Symptoms can include fatigue, weakness, dizziness, headache, shortness of breath and chest pain.
• Bone Pain: Decreased blood flow to the bones leads to periodic spikes in bone pain known as bone crises.
• SCD can also cause avascular necrosis, which is a breakdown of the bone and joint.
• Eye Disease or Blindness: Sickled blood cells can damage the fragile blood vessels in the back of the eye, leading to retina damage called retinopathy. This can lead to blindness.
• Infections: The spleen fails in SCD patients at a young age, decreasing the body’s ability to fight infections.
• Kidney Issues: Blood in the urine (papillary necrosis), frequent urination, kidney disease.

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