Hemoglobinopathy Evaluation Blood Test

What is the purpose of this test?

Order this Hemoglobinopathy Evaluation Blood Test to detect the presence of abnormal hemoglobin S (Hb S) to help confirm the diagnosis of sickle cell anemia. The Hemoglobinopathy Evaluation Blood Test is usually ordered if a person has a positive sickle cell solubility. The Hemoglobinopathy Evaluation Blood Test uses the hemoglobin electrophoresis methodology. It is generally performed as confirmation and to rule out other conditions that may cause an abnormal sickle cell solubility test. In addition, this test may help diagnose other hemoglobin disorders (hemoglobinopathy) such as sickle cell trait, hemoglobin C disease, hemoglobin S-C disease, and thalassemia.

What is hemoglobin (Hb)?

Hemoglobin (Hb) is a protein found in the red blood cells that transfers oxygen from the lungs to the rest of the body. There are several different types of hemoglobin, such as:

• Hb A - comprises approximately 95%-98% of Hb found in adults. This hemoglobin contains two alpha and two beta protein chains.
• Hb A2 - accounts for about 2%-3% of Hb in adults; it is characterized by two alpha and two delta protein chains.
• Hb F - (Fetal hemoglobin) makes up 1%-2% of Hb found in adults; it contains two alpha and two gamma protein chains. Additionally, this is the primary hemoglobin produced by the fetus during pregnancy. The production of Hb F usually drops right after birth and reaches adult levels within 1-2 years.
• Hb S - the primary hemoglobin in individuals with sickle cell disease, which causes the RBC to become misshapen (sickle-shaped), decreasing the cell's survival
• Hb C - is the hemoglobin that can cause minor hemolytic anemia.
• Hb E -the only hemoglobin which may cause no symptoms or generally mild symptoms and is primarily found in individuals of Southeast Asian descent.

What causes hemoglobinopathy?

Unfortunately, some individuals inherit hemoglobin diseases, also known as hemoglobinopathy, in which there is abnormal production or structure of the hemoglobin protein. For example, an abnormal amount of hemoglobin (Hb) S is found in individuals with sickle cell anemia. Sickle cell anemia is an inherited disease that causes the body to create inflexible, "sickle" shaped red blood cells. Red blood cells should be flexible to flow easily through blood vessels; however, sickle cells can get stuck in the blood vessels. 

When should I order a Hemoglobinopathy Evaluation Blood Test?

Individuals may order this test if they have experienced symptoms related to hemoglobinopathy. Patients with abnormal levels of hemoglobins may experience symptoms such as: 

• Severe or chronic pain
• Anemia
• Shortness of breath
• Enlarged spleen
• Frequently recurring infections
• Coughing
• Chest pain
• Fever