What is Sickle Cell?
Sickle cell is a genetic disorder that affects red blood cells. Learn more about what causes this rare condition.
Learn more about what causes this rare condition.
Blood Basics
Blood is made up of 4 components: red blood cells, white blood cells, platelets, and plasma. It has several functions:
- Circulating oxygen and nutrients throughout the body
- Clotting blood to prevent blood loss
- Carrying cells and antibodies to fight infection
- Transporting and filtering waste through the kidneys and liver
- Controlling body temperature
Red blood cells are the most common type of cell in blood. Their job is to carry oxygen from the lungs throughout the body and move carbon dioxide from your organs to your lungs.
What Causes Sickle Cell?
Hemoglobin (Hb) is a protein within red blood cells that does the actual work of carrying oxygen from the lungs to the cells and organs throughout your body. When your red blood cells are healthy, each cell is densely packed with a form of hemoglobin called HbA, the normal form of adult hemoglobin. A healthy hemoglobin protein is balanced with 2 functional alpha (α)-globin and 2 functional beta (β)-globin subunits, forming red blood cells that are smooth and disc-shaped, which allows these healthy cells to move through blood vessels easily.
Hemoglobin (Hb) is a protein within red blood cells that does the actual work of carrying oxygen from the lungs to the cells and organs throughout your body. When your red blood cells are healthy, each cell is densely packed with a form of hemoglobin called HbA, the normal form of adult hemoglobin. A healthy hemoglobin protein is balanced with 2 functional alpha (α)-globin and 2 functional beta (β)-globin subunits, forming red blood cells that are smooth and disc-shaped, which allows these healthy cells to move through blood vessels easily.
Sickle cell is a genetic disease caused by a change (mutation) in both copies of the HBB gene that you inherit from your parents. In people with sickle cell, this mutation affects the hemoglobin protein, which causes people with sickle cell to produce an abnormal form of hemoglobin called hemoglobin Sickle (HbS).
Healthy red blood cells
Sickled red blood cells are rigid and sticky, and can get stuck in blood vessels throughout the body.
Sickled red blood cells
Think of healthy red blood cells as a water balloon: They are flexible and can flatten and squish through even the smallest of blood vessels. Sickled red blood cells, however, have a harder, less flexible consistency—like a water balloon full of ice chips—causing them to slow and/or stick and block blood flow throughout the vessels of the body.
These blockages are called vaso-occlusions and can lead to vaso-occlusive crises, which may cause excruciating pain, among other symptoms and complications.
Healthy red blood cells
Sickled red blood cells
Who Gets Sickle Cell?
Sickle cell affects millions of people throughout the world across a wide range of ethnicities, although in the United States it is often perceived as a disease that only affects the Black community. However, sickle cell can and does affect people of all races.
“Sickle cell is a blood disease and it can affect people of any ethnic background...The reality is that anyone can get this disease, and it can impact you or your family, and you might not care until it matters.”
— Rae, Parent
Prevalence of Sickle Cell
Although it is classified as a rare condition, as of 2019 it is estimated that sickle cell
impacts ~100,000 Americans. Of these:
~1 of 365 Black births
~1 of 16,300 Hispanic American births
Affects men and women equally
Sickle Cell Trait
According to a study published in 2014 by the Centers for Disease Control and Prevention,
as many as
60,000 children in the United States were born with the sickle cell trait. In 2010, based on newborn screening information provided by 13 states, the sickle cell trait was found in:
~73 per 1,000 Black infants
~3 per 1,000 White infants
~2 per 1,000 Asian, Native Hawaiian, or other Pacific Islander infants
~7 per 1,000 Hispanic infants
Although it is classified as a rare condition, as of 2019 it is estimated that sickle cell impacts ~100,000 Americans. Of these:
~1 of 365
Black births
~1 of 16,300
Hispanic births
children
Affects men and
women equally
Sickle Cell Trait
According to a study published in 2014 by the Centers for Disease Control and Prevention, as many as 60,000 children in the United States were born with the sickle cell trait. In 2010, based on newborn screening information provided by 13 states, the sickle cell trait was found in:
~73 per 1,000
Black infants
~73 per 1,000
White infants
~2 per 1,000
Asian, Native Hawaiian, or
other Pacific Islander infants
~7 per 1,000
Hispanic infants
