What is Sickle Cell Disease?
Sickle cell disease is a disease of the hemoglobin. Hemoglobin is what is inside your red blood cells, carrying oxygen all over your body. Most people have what is called Hemoglobin A, which is shaped like a fist and keeps your red blood cells round and squishy. These red blood cells are able to move through your blood vessels easily.
People with sickle cell disease have Hemoglobin S. Hemoglobin S is shaped like a rectangle, and it stretches out your red blood cells (see image below). These stretched out cells (also called sickle cells) are rigid, sticky, and fragile. They get stuck in your blood vessels, and can damage your organs.
Some people have sickle cell trait. A person with sickle cell trait has Hemoglobin A and Hemoglobin S. Since they have Hemoglobin A, they usually don’t have health problems from the Hemoglobin S.
There are other kinds of hemoglobin besides Hemoglobin S and Hemoglobin A. Some people make Hemoglobin C or E, or another unusual type. These types can also be combined with Hemoglobin S to cause different types of sickle cell disease.
How do you get sickle cell disease?
Sickle cell disease is an inherited disease, which means you get it from your parents. In order for a person to have sickle cell disease, at least one of their parents must have sickle cell trait. Their other parent must have sickle cell trait or another hemoglobin trait.
A person with a hemoglobin trait makes two kinds of hemoglobin, but they can only pass down one kind to their child. If two parents both have sickle cell trait (Hemoglobin AS), they can each only pass down one kind of hemoglobin. If one parent passes down Hemoglobin A and the other passes down Hemoglobin S, their baby will have trait. If they both pass down Hemoglobin A, their baby will just make the usual hemoglobin. If they both pass down Hemoglobin S, their baby will have sickle cell disease (Hemoglobin SS).
People can get other types of sickle cell disease if one of their parents passes down Hemoglobin S, and the other parent passes down another unusual hemoglobin, like Hemoglobin C. This person would have Hemoglobin SC.
There are many different types of hemoglobin. It’s important to know what type you have, and what type your partner has.