Common Questions About Sickle Cell Disease

What is the Difference Between Sickle Cell Disease and Sickle Cell Anemia?

Sickle cell anemia refers to the specific and most common type of sickle cell disease where a child has inherited two genes that produce an abnormal hemoglobin called "S" hemoglobin ("SS" disease). There are several other, less common types of sickle cell disease where one gene produces "S" hemoglobin and the other gene produces "C" hemoglobin (SC disease) or a "beta-thalassemia" type of hemoglobin ("S-beta thalassemia").

Taken all together, all of these conditions are referred to as sickle cell disease. Your child will have inherited only one of these types. It is important for you to know which one. Your doctor can explain this to you.

Is Sickle Cell Disease a Common Disease?

Sickle cell disease is a common, life-threatening disease. Each year in the United States, about one in 400 African-American infants are born with sickle cell disease. Sickle cell disease also occurs in children from other racial and ethnic backgrounds. The most common type of sickle cell disease is sickle cell anemia (SS). Other forms of sickle cell disease include hemoglobin SC disease and sickle beta-thalassemia.

Hemoglobin S-C disease tends to be milder than sickle cell anemia. Sickle beta-thalassemia can be mild or severe.

All of these types of sickle cell disease can be identified by the newborn state-screening test.

The focus of this manual is on sickle cell disease. Your child's doctor can explain more about the particular type that your child has when you visit the hospital.

How Does a Child Get Sickle Cell DIsease?

Sickle cell disease is inherited through genes. Genes contain messages that are passed on to the child through the mother's egg and the father's sperm. These messages control such qualities as eye color, blood type, and the kind of hemoglobin a person will have, etc.

Germs do not cause sickle cell disease and you cannot catch it from another person like you catch a cold.

For a child to have any form of sickling disease, each parent will have an abnormal hemoglobin. One possibility is that each parent has sickle cell trait (AS). Another possibility is when one parent has the disease (SS) and the other parent has sickle cell trait (AS).

In hemoglobin SC disease, one parent has sickle cell trait and the other parent has a different trait (hemoglobin C). In sickle beta-thalassemia, one parent has sickle cell trait (or sickle cell anemia) and the other parent carries the trait for beta thalassemia (or has thalassemia major).

Inheritance Pattern When Each Parent Has Sickle Cell Trait

When each parent has sickle cell trait, there is a one in four chance (25% chance) with every pregnancy that the baby could be born with sickle cell disease.

What Does Sickle Cell Disease Do To Blood?

It affects the hemoglobin part of red blood cells. Hemoglobin gives blood its red color and carries oxygen from the lungs to other parts of the body.

Normal red blood cells are round, soft, and flexible. Since they can squeeze through small blood vessels, blood flows easily.

Blood Vessels with round red blood cells

Blood Vessels with mostly sickled cells

In sickle cell disease, red blood cells sometimes change from round to half moon or sickle shaped [ ) ] when the hemoglobin gives off it’s oxygen.

When red blood cells are shaped like a sickle, they are hard and rigid. These sickled cells can get stuck and plug up small blood vessels. The flow of blood and oxygen can be slowed down or stopped.

Pain, damage to parts of the body, and anemia can result.. When the blood flow stops or slows suddenly, the problem is called a sickle cell crisis. The following chart shows how some body organs and tissues may be affected by the plugging of blood vessels.

Plugging of Blood Vessels

* Not all of these problems happen to everyone with sickle cell disease. You need to know, however, that they can happen. Tell your child's doctor right away if you think your child has any of these problems.

Is There A Cure For Sickle Cell Disease?

At this time, there is no cure for most people with sickle cell disease. Medical advances are constantly happening. For up to date information, ask your doctor at the Pediatric Sickle Cell Treatment Center.

Should Other Members Of My Family Be Tested?

Yes. As the sickle hemoglobin abnormality is inherited, your other children may also carry the sickle hemoglobin gene. If both parents are carriers, there is a 25% chance for a child to be born with sickle cell disease. You should know the sickle cell status of yourself, your spouse, and your children (see Diagram 29). Your health care provider, Sickle Cell Treatment Center or Genetic Testing and Counseling Center (listed on page 42-44) can help to determine who should be tested.

Can Sickle Cell Disease Be Diagnosed Before The Baby Is Born?

Yes. Prenatal testing is available. The testing is quite accurate and can tell whether the child has sickle cell trait, sickle cell disease, or neither. If you are pregnant and would like additional information, you may contact the Genetic Testing and Counseling Center nearest you. Centers are listed on page 44 of this guide.

What Is Sickle Cell Trait?

Like other children, the child born with sickle cell trait has two genes for hemoglobin. One gene is normal while the other gene makes sickle hemoglobin.

The normal gene is often referred to using letter (A). The letter (S) is used to refer to the gene that makes sickle hemoglobin. When combined, the letters (AS) refer to the pair of genes that result in sickle cell trait.

Sickle cell trait is a condition. It is not a disease. If a child has only one gene that makes sickle hemoglobin, the child does not have sickle cell disease (SS). The child will not develop the disease later in life; however, the child should know he or she has trait.

This information will be very important to a person when he or she is planning to start having children. If both partners have sickle cell trait, for each pregnancy there is a 25 percent chance the child could be born with sickle cell disease. (See picture of inheritance pattern on page 8).
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