Sickle cell disease (SCD) is a life-long condition that’s inherited, or passed down, from parents to children. In fact, it’s one of the more common inherited diseases. SCD is caused by a mutation (change) in the gene that makes hemoglobin. You need hemoglobin to carry oxygen through your body.
Healthy red blood cells have hemoglobin A that are round and soft. They move easily through small blood vessels to carry oxygen to all parts of the body. With SCD, you make a different type of hemoglobin called hemoglobin S. Hemoglobin S is c-shaped like the farm tool called a sickle. When these sickled cells move through small blood vessels, they get stuck and can block the flow of blood and oxygen. This can damage organs and cause health problems.
Passing down the SCD gene.
Everyone inherits one gene from mom and one from dad. In general, two things need to happen for you to get SCD:
- Both of your parents have the gene that makes hemoglobin S.
- Each parent passes that gene on to you.
Let’s say your mom has one hemoglobin A (healthy gene) and one hemoglobin S (SCD gene) (A S). So does your dad (A S). Here are three possible ways their genes can get passed down to you.
- You inherit the hemoglobin A gene from one parent and the hemoglobin S gene from the other (A S). This means you don’t have SCD, but you do have sickle cell trait. With sickle cell trait, you’ll likely live a normal life with no symptoms. But you can pass your hemoglobin S gene on to your children. And if you meet someone else who also has sickle cell trait, your child may have SCD.
- You inherit hemoglobin A from mom and hemoglobin A from dad (AA). This means you do not have the hemoglobin S gene because you did not get one from either parent. You don’t have SCD or sickle cell trait.
- You inherit the hemoglobin S gene from both parents (SS). With two “S” genes, you have sickle cell disease.
Types of sickle cell disease.
Most people who have SCD have the SS type. Some people have SCD because of other abnormal hemoglobin or another disease called thalassemia. It’s important to talk to your health care team about what type you have, which can include:
- Sickle cell anemia (hemoglobin SS disease)
- Sickle hemoglobin-C disease (hemoglobin SC disease)
- Sickle beta-plus thalassemia (SB+)
- Sickle beta-zero thalassemia (SB 0)
Diagnosis and treatment.
A simple blood test can check for SCD when a baby is born even though symptoms don’t usually show up until about age four to five months. There is no cure for SCD other than a bone marrow transplant, which may be an option for some people. Treatments are available to help reduce symptoms and manage your SCD. Talk to your doctor about a treatment plan that’s best for you.