First officially recognized by the federal government in 1983, National Sickle Cell Awareness Month calls attention to sickle cell disease (SCD), a genetic disease that researchers estimate affects approximately 100,000 Americans.
The term sickle cell disease (SCD) describes a group of inherited red blood cell disorders. SCD is not contagious. A person cannot catch it, like a cold or infection, from someone else. Hemoglobin is a protein in red blood cells that carries oxygen throughout the body. Sickle hemoglobin is not like normal hemoglobin. It can form stiff rods within the red cell, changing it into a crescent, or sickle shape. Sickle-shaped cells are not flexible and can stick to vessel walls, causing a blockage that slows or stops the flow of blood. When this happens, oxygen can’t reach nearby tissues.
Cells in tissues need a steady supply of oxygen to work well. Normally, hemoglobin in red blood cells takes up oxygen in the lungs and carries it to all the tissues of the body. Red blood cells that contain normal hemoglobin are disc shaped (like a doughnut without a hole). This shape allows the cells to be flexible so that they can move through large and small blood vessels to deliver oxygen.
The lack of tissue oxygen can cause attacks of sudden, severe pain, called pain crises. These pain attacks can occur without warning, and a person often needs to go to the hospital for effective treatment. People with SCD have abnormal hemoglobin, called hemoglobin S or sickle hemoglobin, in their red blood cells. People who have SCD inherit two abnormal hemoglobin genes, one from each parent. In all forms of SCD, at least one of the two abnormal genes causes a person’s body to make hemoglobin S. When a person has two hemoglobin S genes, Hemoglobin SS, the disease is called sickle cell anemia. This is the most common and often most severe kind of SCD. Most children with SCD are pain free between painful crises, but adolescents and adults may also suffer with chronic ongoing pain.
The red cell sickling and poor oxygen delivery can also cause organ damage. Over a lifetime, SCD can harm a person’s spleen, brain, eyes, lungs, liver, heart, kidneys, penis, joints, bones, or skin. Sickle cells can’t change shape easily, so they tend to burst apart or hemolyze. Normal red blood cells live about 90 to 120 days, but sickle cells last only 10 to 20 days. The body is always making new red blood cells to replace the old cells; however, in SCD the body may have trouble keeping up with how fast the cells are being destroyed. Because of this, the number of red blood cells is usually lower than normal. This condition, called anemia, can make a person have less energy.
This disease disproportionately affects African Americans –
- About 1 in 13 African American babies is born with sickle cell trait
- About 1 in every 365 African American children is born with sickle cell disease
There are effective treatments that can reduce symptoms and prolong life. Early diagnosis and regular medical care to prevent complications also contribute to improved well-being. For more information visit:
The National Heart, Lung and Blood Institute at http://www.nhlbi.nih.gov/health/health-topics/topics/sca
Sickle Cell Disease Association of America, Inc. at http://www.sicklecelldisease.org/