Hemoglobin is a substance in the red blood cells. It makes the blood red in color, and carries oxygen to all parts of the body. There are many different variations of hemoglobin, called hemoglobin types (this is not the same as the blood type). The type of hemoglobin is inherited, passed down from each parent to the child in the genes. The most common hemoglobin type is "A". As long as a person has some hemoglobin A, the red blood cells stay smooth and round, and can deliver oxygen normally to the body.
SICKLE CELL DISEASE
Sickle cell disease (sickle cell anemia, sickle hemoglobin C disease, sickle hemoglobin D disease, sickle hemoglobin E disease, and sickle beta thalassemia) is a group of hereditary disorders that affect the red blood cells. Under certain conditions, the blood cells of infants with sickle cell disease become sickle-shaped, causing obstruction in the blood vessels which leads to pain and/or damage to the tissues. The most serious problem for infants is infections, which can prove fatal. Newborns diagnosed with sickle cell disease are placed on antibiotic therapy and parents are provided information and instruction about preventive health measures as well as identification of symptoms requiring prompt medical attention. Sickle cell disease and other hemoglobinopathies are present in all population groups but are more prevalent in persons of African, Mediterranean, Asian, Southeast Asian, Caribbean, and South and Central American origins. In California, the incidence of sickle cell disease is about 1 per 4,400. The Newborn Screening Program detects approximately 125 cases each year.
What is Sickle Cell Disease?
In sickle cell disease, there is no hemoglobin A. Instead, there is only sickle hemoglobin, called hemoglobin S, or there may be hemoglobin S and another type of hemoglobin (C, D, E, or beta thalassemia). These hemoglobins cause the red blood cells to be hard and sticky, and change to a banana ( "sickle" ) shape. These sticky, sickled cells can clog up the small blood vessels so the blood can't bring oxygen to the tissues. That can cause pain and damage in the area. Eventually, the sickling can affect growth and cause organ damage. The most serious problem for babies with sickle cell disease is infections. These babies can easily develop high fevers or pneumonia which require prompt treatment.
There are several types of sickle cell disease. Hemoglobin SS (also called sickle cell anemia) is the most common. Other types of sickle cell disease include hemoglobin SC disease (sickle "C" disease), hemoglobin SD or SE, and hemoglobin S beta thalassemia disease (sickle beta thal disease). Some types of sickle cell disease can cause more problems than others. For example, hemoglobin SC is often less serious than hemoglobin SS. Sickle cell disease can also affect different people in different ways, so it may be hard to know how serious it will be for a particular person.
What is the Treatment for Sickle Cell Disease?
Babies with certain types of sickle cell disease are treated with penicillin every day and get special immunizations (shots) to help prevent infections. Parents work closely with their child's doctor, the children's blood specialist (hematologist) and the sickle cell clinic. They learn how to care for their baby and recognize when to take the baby to the doctor to treat problems early. Good nutrition and extra fluids are very important. Sometimes hospitalization is needed for treatment with IV (medicine given through a thin tube into a vein) antibiotics and fluids. When the child is older, (s)he may occasionally need to be given blood.
Medications to decrease or prevent sickling of the blood are being used with some patients; effectiveness and side effects are being carefully studied. For a few people with sickle cell disease, a bone marrow transplant can be done to "cure" the disease, but this is still a high-risk procedure. A new procedure called a related-donor cord blood transplant may be possible for some families with an affected child who are planning to have another child. A blood specialist can discuss all the options with the family.
What Other Hemoglobin Conditions are Detected by Newborn Screening?
There are other combinations of hemoglobin types that babies can inherit, in which there is little or no usual hemoglobin A. These conditions are uncommon, and do not cause the red blood cells to sickle. Examples of these include hemoglobin CC, hemoglobin C beta thalassemia, hemoglobin DD, hemoglobin CE, hemoglobin DE, and hemoglobin DC. Some of these conditions cause very few problems, while others can cause health problems.