General Condition Information
Other Names
- Hemoglobin C trait
- Hemoglobin C trait (carrier)
- Hemoglobin D trait
- Hemoglobin D trait (carrier)
- Hemoglobin E trait
- Hemoglobin E trait (carrier)
- Hemoglobin other trait (carrier)
- Hemoglobin trait (C, D, E, or Unidentified)
- Hemoglobin trait conditions
Condition Type
Birth Prevalence
Hemoglobin traits are very common and can occur in any race or ancestral groups. However, hemoglobin traits are typically more common in African American, West African, East Indian, Southeast Asian, and Mediterranean backgrounds.
Screening Finding
What is hemoglobin trait
Hemoglobin traits are a group of inherited (genetic) conditions that affect some of the hemoglobin in blood. Hemoglobin is a part of your red blood cells, which carry oxygen in your body. In hemoglobin trait, some of the body’s normal hemoglobin is replaced with hemoglobin that is changed slightly, which is also called a variant hemoglobin.
Normal blood cells are round and shaped like doughnuts. Babies with hemoglobin trait typically have enough normal hemoglobin to have normal shaped red blood cells, so do not usually have any signs and symptoms.
Newborn Screening and Follow-Up
Hemoglobin traits may be found in the same newborn screening test done testing for S,S disease. This screening requires collecting a small amount of blood from your baby’s heel. To learn more about this process, visit the Blood Spot Screening page.
Screening measures certain types of hemoglobins in your baby’s blood. Babies with different types of hemoglobins (variant hemoglobins) might have hemoglobin trait.
If your baby’s blood spot screening result shows that your baby might have a hemoglobin trait, your baby’s health care provider should let you know before or at your baby’s first well child visit. Together, you will discuss the results.
An out-of-range screening result suggesting hemoglobin trait usually means that your baby does have a hemoglobin trait, but your baby will need more follow-up testing to know for sure and to help determine which hemoglobin trait your baby has. To learn more about screening results, visit the Blood Spot Screening Results page.
Your baby may need the following tests after a hemoglobin trait screening result:
- Blood tests
- Genetic testing using a blood sample
False-positive newborn screening results for this condition are rare. However, screening samples that are collected after a baby receives red blood cells from someone else (a red cell transfusion) will be inaccurate.
Condition Details
Newborn screening helps babies lead healthier lives. If your baby has a hemoglobin trait screening result, follow up with your baby’s health care provider.
Most individuals with hemoglobin trait will likely never have any signs and symptoms of the condition.
Hemoglobin traits are caused by a change in the HBB gene. This gene gives the body instructions for making beta-globin, a protein found in hemoglobin.
The change in HBB creates an abnormal beta-globin called a variant hemoglobin.
Hemoglobin trait is a genetic condition. Babies inherit it from their biological (birth) parents. To learn more about genetic conditions, visit MedlinePlus Genetics.
- Babies inherit hemoglobin trait when one parent passes down a nonworking HBB gene to their baby.
- People with one normal copy and one hemoglobin variant copy of the HBB gene are said to have hemoglobin trait (sometimes also called being a carrier).
- People with hemoglobin trait may pass down a hemoglobin variant copy of the gene to their children.
- If two parents both have hemoglobin traits, each have a hemoglobin variant copy of the HBB They have a 1 in 2 chance of having a child with hemoglobin trait and they have a 1 in 4 chance of having a child with a hemoglobin disease.
- People with hemoglobin trait often do not know they are carriers of a hemoglobin variant copy of the HBB gene before having a child with a hemoglobin variant trait or a hemoglobin disease.
- Parents who already have a child with a hemoglobin trait still have a 1 in 2 chance of having another child with a hemoglobin trait. This 1 in 2 chance stays the same for all future children.
- Genetic counselors and medical geneticists can help families learn about this condition and the chance of having children with it. Visit the National Society of Genetic Counselors to find a genetic counselor and the American College of Medical Genetics and Genomics to find a medical geneticist.
Treatment and Management
Most individuals with hemoglobin trait will never need treatment. Treatment is only usually needed if an individual starts to have signs or symptoms.
Community-based organizations (CBOs) are local agencies that provide services, education, and support to families affected by hemoglobin conditions like hemoglobin trait. To find a CBO near you, please visit the Sickle Cell Disease Association of America’s list of member organizations.