Sickle Cell Trait

En Español 

Sickle cell trait is an inherited blood condition. It is not a disease. It occurs when a person has one gene for normal hemoglobin and one for sickle hemoglobin. (Hemoglobin is a protein in red blood cells and carries oxygen to your body.) Genes control the physical makeup of a person, such as height and eye color. Every person has two genes for hemoglobin. One gene is inherited from the mother and one from the father. To have sickle cell trait means a person carries one gene for sickle cell hemoglobin. This gene can be passed along to his or her children.

What Can Happen If You Have Sickle Cell Trait?

Figure showing each child has a 1 in 4 (25%) chance of having sickle cell disease if both parents carry the sickle cell trait.Most people with sickle cell trait lead completely normal lives and usually show no outward signs of it. People with the trait will not get sickle cell disease. But they may have severe problems with very extreme physical activity. It is important that your doctor knows if you or your child have sickle cell trait. Very rarely individuals with sickle cell trait can have additional problems such as a very rare form of kidney cancer found only in individuals with sickle cell trait.

When one parent has sickle cell trait and the other parent has sickle cell trait or another hemoglobin trait (such as hemoglobin C or beta-thalassemia), there is a one-in-four chance that their baby will be born with sickle cell disease. There is a one-in-two chance that their baby will be born with the trait and a one-in-four chance that their baby will not have sickle cell disease or trait. 

Who Can Have Sickle Cell Trait?

People of different ethnic backgrounds can have sickle cell trait. These include persons whose ancestors come from Africa, Asia, India, Indigenous America, Latin America, Mediterranean, and Middle East regions. 

In the United States, African Americans have the highest rate of sickle cell disease and sickle cell trait. In fact, about one in every 400 African-American babies is born with the disease, and about one in every 12 is born with sickle cell trait. All newborns in Texas are tested for sickle cell disease and trait. 

How Can You Find Out If You Have Sickle Cell Trait?

It is very important to know if you or your spouse or partner have the sickle cell trait before you have a baby. Remember, people with sickle cell trait will never get the disease. But they carry a gene that could affect their children. If both partners carry a trait for an abnormal hemoglobin, even if it is not the same one, they may have a baby with a serious blood disease. 

If you were born in Texas after November 1, 1983, you may get your newborn test result by contacting your birth doctor or your birth hospital. If you were tested years ago and told you did not have a sickle cell trait, you should be tested again. Some tests used years ago were not as accurate as tests used today. Be informed. Learn your hemoglobin type. 

Sickle Cell Trait Resources 

Sickle Cell Resources 

View sickle cell resources including consultant and provider lists, educational information and videos, direct service and support organizations as well as other information. Read about sickle cell disease. 

This site and related brochures do not take the place of an informed discussion between a patient and their healthcare provider. 

Contact Us

Texas Department of State Health Services
Newborn Screening Unit
Phone: 1-800-252-8023 ext. 3957 
Email: newborn@dshs.state.tx.us 


External links to other sites are intended to be informational and do not have the endorsement of the Texas Department of State Health Services. Those sites may also not be accessible to persons with disabilities. 

Last updated May 18, 2018