Sickle Cell Disease

What is Sickle Cell Disease?

Sickle cell disease (SCD) is an inherited blood disorder that affects red blood cells. SCD affects millions of people throughout the world and is particularly common among those whose ancestors came from sub-Saharan Africa; Spanish-speaking regions in the Western Hemisphere (South America, the Caribbean, and Central America); Saudi Arabia; India; and Mediterranean countries such as Turkey, Greece, and Italy. A child of parents who each have one affected gene has a 25 percent chance of inheriting the disease. It occurs in both men and women. Hemoglobin is the main substance of the red blood cell. It helps red blood cells carry oxygen from the air in our lungs to all parts of the body. Normal red blood cells contain hemoglobin A. Normal red blood cells that contain hemoglobin A are soft and round and can squeeze through tiny blood tubes (vessels). Normally, red blood cells live for about 120 days before new ones replace them. Red blood cells in people with SCD change into the shape of a banana or a sickle-shaped (crescent-shaped), the curved farming tool from which the disease takes its name.

What are the Symptoms of Sickle Cell Disease?

People who have sickle cell disease can experience the following symptoms:

• Anemia: Sickle cells are fragile and can break apart easily. Additionally, they have a shorter lifespan than regular red blood cells. As sickle cells die or break apart, they can leave sickle cell sufferers with a shortage of red blood cells (anemia). Without enough red blood cells, the body can't get enough oxygen, causing fatigue.
• Swelling: Sickle-shaped red blood cells can create blockages that keep blood flowing freely to the hands and feet.
• Infections: Sickle cells can damage your spleen, leaving you more vulnerable to infections. Children with sickle cell anemia are often given vaccinations and antibiotics to prevent infections.
• Impaired Vision: Tiny blood vessels that supply your eyes can become plugged with sickle cells. This can damage the retina — the portion of the eye that processes visual images — and lead to vision problems.
• Delayed growth or puberty: A shortage of healthy red blood cells can deprive infants and children of the oxygen and nutrients they need for growth and development. Sickle cell disease can slow growth in infants and children and delay puberty in teenagers.
• Episodes of pain: Periodic episodes of pain, called Vaso-occlusive Crisis (VOC), are a major symptom of sickle cell anemia. Pain develops when sickle-shaped red blood cells create blockages that limit or stop blood flow through tiny blood vessels to your chest, abdomen and joints. Pain can also occur in your bones. The pain varies in intensity and can last for a few hours to a few weeks. Some people have only a few pain crises a year. Others have a dozen or more pain crises a year. A severe pain crisis requires a hospital stay. Some adolescents and adults with sickle cell anemia also have chronic pain, which can result from bone and joint damage, ulcers, and other causes.

Because sickle cells have the potential to create blockages within blood vessels, people suffering from sickle cell disease are at risk for developing serious complications, such as stroke, pulmonary hypertension, acute chest syndrome, leg ulcers, gall stones, blindness and pregnancy complications.

How is Sickle Cell Disease Treated?

There is currently no universal cure for sickle cell disease; however, recent advances in medicine -- including management of vaso-occlusive crises and potential gene therapy treatments -- have provided sickle cell disease patients with reasons for hope.