What is Hemoglobin C Trait?

Hemoglobin C trait is a small change in a gene that helps make hemoglobin in red blood cells. Hemoglobin is a protein that carries oxygen from your lungs to the rest of your body.

People with normal hemoglobin have only one kind, called hemoglobin A.

People with hemoglobin C trait have:

• One normal hemoglobin gene (A)
• One changed hemoglobin gene (C)

Hemoglobin C Trait Is Not a Disease

It’s different from hemoglobin C disease or hemoglobin SC disease. Most people with hemoglobin C trait feel healthy and don’t have any symptoms.

• Hemoglobin C trait does not turn into hemoglobin C disease or hemoglobin SC disease
• A child must inherit certain genes from both parents to have one of these diseases

What Are Hemoglobin C Disease and Hemoglobin SC Disease?

• Hemoglobin C disease happens when a person gets two hemoglobin C genes. It can cause mild anemia (low red blood cells), but usually doesn’t cause serious health problems. It is not a type of sickle cell disease.
• Hemoglobin SC disease happens when a person gets one hemoglobin C gene and one sickle cell gene (S). This is a type of sickle cell disease. It can cause red blood cells to become sickle-shaped, block blood flow, and cause pain. People with this disease need regular medical care.

Who Can Have Hemoglobin C Trait?

Hemoglobin C trait is more common in people with family from:

• West Africa
• The Caribbean
• Latin America
• Italy or Greece

But anyone can have it.

In the U.S., about 1 in 40 Black or African American babies are born with hemoglobin C trait.

What if My Baby Screens Positive for trait?

1.) Talk to Your Baby’s Doctor 

Ask questions and learn what the results mean. 

2.) Get Follow-Up Testing

Doctors will do more tests to confirm the result. Your pediatrician may refer you to a pediatric hematologist (a blood specialist). Work with them to schedule the appointment. The hematologist will help confirm your baby’s newborn screening results.

Some pediatricians who are familiar with hemoglobin traits may order the testing themselves.  This is fine, as long as you receive and understand the results.  If you have questions that your pediatrician cannot answer, you can ask for a referral to a hematologist.

This visit and test should happen when your baby is between 6 months and 1 year old.