What is Sickle Hemoglobin?

Sickle hemoglobin, also referred to as S. hemoglobin, is a common form of abnormal hemoglobin that serves as the source for both the sickle cell trait and sickle cell anemia. Predominantly found in individuals of African descent, the presence of sickle hemoglobin, also called the sickle gene, can only be confirmed through a blood test. In instances where the inheritance of sickle genes result in sickle cell anemia, there is no cure for the disease — there are only preventative measures for averting pain crises and treatment for managing pain episodes, which can last for hours or days, depending on intensity.

Though it is rare, abnormal hemoglobin formation occurs when there is an alteration in the hemoglobin genetic code. In the case of sickle hemoglobin, its formation is the result of the absence of a single amino acid. The mutated hemoglobin is less fluid than typical hemoglobin, and as a result, polymers are formed within the cell. These polymers are what bind together to distort cell formation giving it a sickle, or crescent, shape.

When an individual inherits a single sickle hemoglobin gene, he or she possesses the sickle cell trait, or S. hemoglobin trait, and is only a carrier for sickle cell disease. The amount of sickle hemoglobin present in a carrier is usually minimal and not sufficient to alter the shape of red blood cells. Individuals who are carriers rarely experience health issues associated with the single sickle gene and will not develop sickle cell anemia.

Those who inherit the sickle hemoglobin gene from both parents can only produce sickle hemoglobin, meaning the person has sickle cell anemia. With this type of anemia, the sickle shape of the red blood cells can inhibit blood flow resulting in pain, an increased risk of stroke, and an increased susceptibility to infection. A diagnosis of sickle cell anemia generally occurs before a child is six months old.

Symptoms of sickle cell anemia include abdominal pain, jaundice, joint pain, fatigue, chest pain, and susceptibility to infections. Symptoms can lead to full pain episodes that can be managed through the use of a variety of treatments. Children with sickle cell anemia will generally become symptomatic around four months of age, so it is important for a symptomatic child to be seen by a hematologist as soon as possible and a penicillin regimen established to fight infections.

Bone pain is one of the most common crises experienced by those with sickle cell anemia. In many cases, the onset of such pain crises are precipitated by an extreme temperature change, dehydration, or infection. Treatments for sickle cell anemia include the use of antibiotics, pain medications, vitamin supplements, blood transfusions, and surgery, including bone marrow transplant. Complications, such as joint inflammation, bone problems, and gallbladder disease, are treated as they occur.