What is hemoglobin?
Hemoglobin (Hb) is the special protein within the red blood cell that carries oxygen from the lungs to the rest of the body.

Where does your hemoglobin come from?
Your hemoglobin type is inherited through family genes. The color of your hair, the color of your eyes, your body build, and your hemoglobin type are all examples of things about you that are determined by genes. You receive one gene for hemoglobin type from your mother and one from your father.

Hemoglobin A or normal adult hemoglobin is the most common type. There are over 500 different types or variations of hemoglobin.

What is hemoglobin C?
Hemoglobin C is a hemoglobin variant often found in West Africans and descendants from that area. In the United States, hemoglobin C occurs in 2 - 3% of the African American population.

What is hemoglobin C trait?
People with hemoglobin C trait inherit a normal hemoglobin gene (Hb A) from one parent and a hemoglobin C gene (Hb C) from the other parent.

This results in hemoglobin AC or hemoglobin C trait. A person with hemoglobin C trait may also be called a hemoglobin C carrier. Hemoglobin C trait is not a disease. It will not turn into a disease. Hemoglobin C trait should cause no health problems and requires no special medical care.

Counseling regarding the trait is important because the hemoglobin gene can be passed on to a carrier's child.

The most important aspect of identifying people with Hemoglobin C trait is informing them of their risk of having a child with a serious disease.

What is hemoglobin C disease?
Hemoglobin C disease occurs when a person inherits the hemoglobin C gene from each parent (Hb CC). The red cells contain only hemoglobin C and no normal hemoglobin A. Most people with hemoglobin C disease lead fairly healthy lives and live to a normal age. Symptoms that may occur are mild anemia (low red blood counts), slightly large spleen (an organ on the left side of your abdomen), and gallstones. Genetic counseling can help the family better understand hemoglobin C disease.

What is hemoglobin SC disease?
Persons with hemoglobin SC disease inherit a hemoglobin S (sickle) gene from one parent and a hemoglobin C gene from the other parent. Hemoglobin SC disease is a form of sickle cell disease. The person with hemoglobin SC disease has red cells which sickle. The sickling of red cells may cause the following medical problems: anemia (low red blood counts), painful crises, enlarged spleen, infections, lung problems and strokes.

Any child with hemoglobin SC disease needs close medical attention from the local doctor. The child should also be followed by a Comprehensive Care Program which offers specialized services for children with sickle cell disease. The caretaker should receive teaching about the disease and understand the special needs of the child.

Patterns of Inheritance
If two people with hemoglobin C trait have a child, there is a 50% risk that the child will have hemoglobin C trait (hemoglobin AC). There is also a 25% chance the child will be unaffected (hemoglobin AA) and a 25% chance that the child will have hemoglobin C disease (hemoglobin CC). These risks are true for each pregnancy.

If one parent has hemoglobin C trait and the other has normal hemoglobin, it is unlikely that any of their children will have hemoglobin C disease. However, there is a 50% chance with each pregnancy that the child will have hemoglobin C trait (Hb AC).

If one parent has sickle cell trait (Hb AS) and one parent has hemoglobin C trait (Hb AC) there is a 25% risk that the child will have sickle cell trait and a 25% risk that the child will have hemoglobin C trait. There is also a 25% risk the child will be unaffected (Hb AA) and a 25% risk that the child will have sickle cell disease (Hb SC). These risks are true for each pregnancy.

How can I find out if my child has Hemoglobin C?
The Iowa Newborn Screen includes a test (hemoglobin electrophoresis) for hemoglobin C. The hemoglobin electrophoresis will identify persons with hemoglobin C trait, hemoglobin C disease and hemoglobin SC disease. The test takes only a few drops of blood which is obtained from a prick to the baby's heel. This test is done before the newborn leaves the hospital. If the first test shows hemoglobin C, a second test will be done when the baby is 4 months old to confirm the diagnosis. A hemoglobin electrophoresis should be done for older children or adults in the family if your doctor feels hemoglobin C trait or disease is in question.

What services are available in Iowa for identifying persons with Hemoglobin C?

• Screening of newborns through the Iowa Newborn Metabolic Screening Program (INMSP) includes a test for hemoglobin C.
• Screening of family members for hemoglobin C and other abnormal hemoglobins for a small fee.
• Genetic counseling for affected families through the Regional Genetic Consultation Services (RGCS) or at the University of Iowa Hospitals & Clinics, Iowa City.
• The Hemoglobinopathy Comprehensive Care Program nurses are available to provide community education so schools, churches, and other interested groups can learn more about hemoglobin C.

For More Information Contact:
Hemoglobinopathy Screening and Comprehensive Care Program
Center for Disabilities and Development, 254-1 CDD
Iowa City, Iowa 52242-1011
(319) 356-1400 or 356-4328

This educational brochure was printed with funds obtained from the Children's Miracle Network Telethon.

Developed by:

Renai Chavez, RN

Roger H. Giller, MD

Sharon K. McMillan, RN

Judy A. Miller, RN, MA