Genetic Mutations & Gene Therapy

What is Sickle Cell Anemia? 

Sickle cell anemia is an inherited form of anemia — a condition in which there aren't enough healthy red blood cells to carry adequate oxygen throughout your body.

Normally, your red blood cells are flexible and round, moving easily through your blood vessels. In sickle cell anemia, the red blood cells become rigid and sticky and are shaped like sickles or crescent moons. These irregularly shaped cells can get stuck in small blood vessels, which can slow or block blood flow and oxygen to parts of the body.

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Symptoms:

Signs and symptoms of sickle cell anemia usually show up after an infant is 4 months old and may include:

• Anemia. Sickle cells are fragile. They break apart easily and die, leaving you chronically short on red blood cells. Red blood cells usually live for about 120 days before they die and need to be replaced. However, sickle cells die after only 10 to 20 days. The result is a chronic shortage of red blood cells, known as anemia. Without enough red blood cells in circulation, your body can't get the oxygen it needs to feel energized. That's why anemia causes fatigue.
• Episodes of pain. Periodic episodes of pain, called crises, are a major symptom of sickle cell anemia. Pain develops when sickle-shaped red blood cells block blood flow through tiny blood vessels to your chest, abdomen and joints. Pain can also occur in your bones. The pain may vary in intensity and can last for a few hours to a few weeks. Some people experience only a few episodes of pain. Others experience a dozen or more crises a year. If a crisis is severe enough, you may need to be hospitalized.
• Hand-foot syndrome. Swollen hands and feet may be the first signs of sickle cell anemia in babies. The swelling is caused by sickle-shaped red blood cells blocking blood flow out of their hands and feet.
• Frequent infections. Sickle cells can damage your spleen, an organ that fights infection. This may make you more vulnerable to infections. Doctors commonly give infants and children with sickle cell anemia antibiotics to prevent potentially life-threatening infections, such as pneumonia.
• Delayed growth. Red blood cells provide your body with the oxygen and nutrients you need for growth. A shortage of healthy red blood cells can slow growth in infants and children and delay puberty in teenagers.
• Vision problems. Some people with sickle cell anemia experience vision problems. Tiny blood vessels that supply your eyes may become plugged with sickle cells. This can damage the retina — the portion of the eye that processes visual images.
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Risk Factors :

The risk of inheriting sickle cell anemia comes down to genetics. For a baby to be born with sickle cell anemia, both parents must carry a sickle cell gene.

The gene is more common in families that come from Africa, India, the Mediterranean, Saudi Arabia, and South and Central America. In the United States, it most commonly affects blacks and Hispanics.

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Treatments and Drugs 

• Antibiotics. Children with sickle cell anemia may begin taking the antibiotic penicillin when they're about 2 months of age and continue taking it until they're 5 years old. Doing so helps prevent infections, such as pneumonia, which can be life-threatening to an infant or child with sickle cell anemia. Antibiotics may also help adults with sickle cell anemia fight certain infections.
• Pain-relieving medications. To relieve pain during a sickle crisis, your doctor may advise over-the-counter pain relievers and application of heat to the affected area. You may also need stronger prescription pain medication.
• Hydroxyurea (Droxia, Hydrea). When taken daily, hydroxyurea reduces the frequency of painful crises and may reduce the need for blood transfusions. It may be an option for adults with severe disease. Hydroxyurea seems to work by stimulating production of fetal hemoglobin — a type of hemoglobin found in newborns that helps prevent the formation of sickle cells. Hydroxyurea increases your risk of infections, and there is some concern that long-term use of this drug may cause tumors or leukemia in certain people. Your doctor can help you determine if this drug may be beneficial for you.
• Blood transfusions
  In a red blood cell transfusion, red blood cells are removed from a supply of donated blood. These donated cells are then given intravenously to a person with sickle cell anemia.
  
  
  Immunizations to prevent infections
  Because infections can be very serious in children with sickle cell anemia, your doctor will likely recommend your child receive the available vaccinations.
• For a full list of treatments and drugs, click here.
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