The exact number of people living with SCD in the U.S. is unknown. Working with partners, the CDC supports projects to learn about the number of people living with SCD to better understand how the disease impacts their health.
It is estimated that:
- SCD affects approximately 100,000 Americans.
- SCD occurs among about 1 out of every 365 Black or African-American births.
- SCD occurs among about 1 out of every 16,300 Hispanic-American births.
- About 1 in 13 Black or African-American babies is born with sickle cell trait (SCT).
What is Sickle Cell Disease?
Sickle Cell Disease (SCD) is a group of inherited red blood cell disorders. Healthy red blood cells are round, and they move through small blood vessels to carry oxygen to all parts of the body. In someone who has SCD, the red blood cells become hard and sticky and look like a C-shaped farm tool called a “sickle”. The sickle cells die early, which causes a constant shortage of red blood cells. Also, when they travel through small blood vessels, they get stuck and clog the blood flow. This can cause pain and other serious problems such infection, acute chest syndrome and stroke.
What is Sickle Cell Trait?
Sickle cell trait (SCT) is not a mild form of sickle cell disease. Having SCT simply means that a person carries a single gene for sickle cell disease (SCD) and can pass this gene along to their children. People with SCT usually do not have any of the symptoms of SCD and live a normal life. Hemoglobin is found in red blood cells and it gives blood its color. It carries oxygen to all parts of the body. Hemoglobin is made from two similar proteins, one called alpha-globin and one called beta-globin, that “stick together.” Both proteins must be present and function normally for the hemoglobin to carry out its job in the body. People with SCT have red blood cells that have normal hemoglobin and abnormal hemoglobin. Genes are the instructions that control how red blood cells make alpha- and beta-globin proteins. All people have two genes for making beta-globin. They get one beta-globin gene from each parent. SCT occurs when a person inherits a gene for sickle beta-globin from one parent and a gene for normal beta-globin from the other parent. This means the person won’t have sickle cell disease, but will be a trait “carrier” and can pass it on to their children.
Two individuals that carry the sickle cell trait, has a 1 in 4 chances of having a child with sickle cell disease.