Hemoglobinopathy Evaluation
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- Also Known As:
- Hemoglobin Evaluation
- Hb ELP
- Hb IEF
- Sickle Cell Screen
- Hemoglobin Fractionation
- Formal Name:
- Hemoglobin Electrophoresis|Hemoglobin Isoelectric Focusing|Hemoglobin by HPLC|Hemoglobin by Capillary Electrophoresis

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At a Glance
Why Get Tested?
To screen for and/or diagnose a hemoglobin disorder called a hemoglobinopathy
When To Get Tested?
When you have abnormal results on a complete blood count (CBC) and/or blood smear that suggest an abnormal form of hemoglobin (hemoglobinopathy); when you have symptoms of hemolytic anemia such as weakness and fatigue and your health care practitioner suspects that you have a hemoglobinopathy; when you have a family history of hemoglobinopathy; as part of newborn screening
Sample Required?
A blood sample drawn from a vein; sometime a blood sample is collected by pricking a finger (fingerstick) or the heel (heelstick) of an infant and a few drops of blood are collected in a small tube.
Test Preparation Needed?
None
What is being tested?
A hemoglobin disorder or hemoglobinopathy is an inherited blood disorder in which there is an abnormal form of hemoglobin (variant) or decreased production of hemoglobin (thalassemia). A hemoglobinopathy evaluation is a group of tests that determines the presence and relative amounts of abnormal forms of hemoglobin in order to screen for and/or diagnose a hemoglobin disorder.
Hemoglobin (Hb) is the protein in red blood cells (RBCs) that binds to oxygen in the lungs and allows RBCs to carry the oxygen throughout the body, delivering it to the body’s cells and tissues. Hemoglobin consists of one portion called heme, which is the molecule with iron at the center, and another portion made up of four globin (protein) chains. Depending on their structure, the globin chains, depending on their structure, have different designations: alpha, beta, gamma, and delta. The types of globin chains that are present are important in the function of hemoglobin and its ability to transport oxygen.
Normal hemoglobin types include:
- Hemoglobin A: makes up about 95%-98% of Hb found in adults; it contains two alpha and two beta protein chains.
- Hemoglobin A2: makes up about 2%-3% of Hb in adults; it has two alpha and two delta protein chains.
- Hemoglobin F (fetal hemoglobin): makes up to 1%-2% of Hb found in adults; it has two alpha and two gamma protein chains. This is the primary hemoglobin produced by the fetus during pregnancy; its production usually falls shortly after birth and reaches adult levels by 1-2 years.
Hemoglobinopathies occur when changes (variants) in the genes that provide information for making the globin chains cause changes in the proteins. These genetic variants may result in a reduced production of one of the normal globin chains or in the production of structurally altered globin chains. Approximately 7% of the world’s population carry at least one copy of a genetic variant in one of the hemoglobin chains (carrier), and the rate can vary dramatically based on ethnicity. Genetic variants may affect the structure of the hemoglobin, its behavior, its production rate, and/or its stability. The presence of abnormal hemoglobin within RBCs can alter the appearance (size and shape) and function of the red blood cells.
Red blood cells containing abnormal hemoglobin (hemoglobin variants) may not carry oxygen efficiently and may be broken down by the body sooner than usual (a shortened survival), resulting in hemolytic anemia.
While there are more than 1,000 hemoglobinopathies currently described and novel forms are still being discovered, some of the most common hemoglobin variants include:
- Hemoglobin S, the primary hemoglobin in people with sickle cell disease that causes the RBC to become misshapen (sickle), decreasing the cell’s survival
- Hemoglobin C, which can cause a minor amount of hemolytic anemia
- Hemoglobin E, which may cause no symptoms or generally mild symptoms
Thalassemia is a condition in which a gene variant results in reduced production of one of the globin chains. This can upset the balance of alpha to beta chains, leading to decrease in hemoglobin A, causing abnormal forms of hemoglobin to form (alpha thalassemia) or causing an increase of minor hemoglobin components, such as Hb A2 or Hb F (beta thalassemia).
Hemoglobinopathies can be thought of as an alteration of quality of the hemoglobin molecule (how well it functions), while thalassemias are an alteration of quantity.
Many other less common hemoglobin variants exist. Some are silent – causing no signs or symptoms – while others affect the function and/or stability of the hemoglobin molecule.
A hemoglobinopathy evaluation typically involves tests that determine the types and amounts of hemoglobin. Information from these tests, along with results from routine tests such as a complete blood count (CBC) and blood smear, aid in establishing a diagnosis.
Common Questions
View Sources
Sources Used in Current Review
2020 review performed by Sydney Webb Strickland, PhD, DABCC, Director, LabCorp.
(2020) Baby’s First Test Available online at https://www.babysfirsttest.org/newborn-screening/states. Accessed on 4/23/2020.
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Weatherall, DJ (2008). Hemoglobinopathies worldwide: present and future. Curr Mol Med 8(7):529-9.
Sources Used in Previous Reviews
Harmening D. Clinical Hematology and Fundamentals of Hemostasis, Fifth Edition. F.A. Davis Company, Philadelphia, 2009, Chapters 11 and 12.
Henry’s Clinical Diagnosis and Management by Laboratory Methods. 21st ed. McPherson R, Pincus M, eds. Philadelphia, PA: Saunders Elsevier: 2007, Pp 520-522.
Clarke, W. and Dufour, D. R., Editors (2006). Contemporary Practice in Clinical Chemistry. AACC Press, Washington, DC, Pp 213-224.
(February 8, 2012) MedlinePlus Medical Encyclopedia. Hemoglobin electrophoresis. Available online at http://www.nlm.nih.gov/medlineplus/ency/article/003639.htm. Accessed December 2012.
(October 5, 2011) Cheerva A. Alpha Thalassemia. Medscape Review article. Available online at http://emedicine.medscape.com/article/206397-overview. Accessed December 2012.
(January 3, 2012) Maakaron J. Sickle Cell Anemia. Medscape Review article. Available online at http://emedicine.medscape.com/article/205926-overview. Accessed December 2012.
(May 16, 2012) Carter S. Hemoglobin C Disease. Medscape Reference Article. Available online at http://emedicine.medscape.com/article/200853-overview. Accessed December 2012.
(©2012 University of Rochester) Health Encyclopedia. Sickle Cell Disease. Available online at http://www.urmc.rochester.edu/Encyclopedia/Content.aspx?ContentTypeID=85&ContentID=P00101. Accessed December 2012.
(©2012 University of Rochester) Health Encyclopedia. Alpha Thalassemia. Available online at http://www.urmc.rochester.edu/Encyclopedia/Content.aspx?ContentTypeID=85&ContentID=P00074. Accessed December 2012.
(©2012 University of Rochester) Health Encyclopedia. Beta Thalassemia. Available online at http://www.urmc.rochester.edu/Encyclopedia/Content.aspx?ContentTypeID=85&ContentID=P00081. Accessed December 2012.
(©2012 Mayo Medical Laboratories) Test Catalog. Thalassemia and Hemoglobinopathy Evaluation. Available online at http://www.mayomedicallaboratories.com/test-catalog/Overview/84158 through. Accessed December 2012.
(Published online August 2011) Kohne E. Hemoglobinopathies. Dtsch Arztebl Int. 2011 August; 108(31-32): 532–540. Available online at http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3163784/. Accessed December 2012.
(©2013 St. Jude Children’s Research Hospital) Hemoglobin C Trait. Available online at http://www.stjude.org/stjude/v/index.jsp?vgnextoid=f1b0db6324d6f110VgnVCM1000001e0215acRCRD. Accessed February 2013.
(September 16, 2011) Centers for Disease Control and Prevention. Sickle Cell Disease, Data and Statistics. Available online at http://www.cdc.gov/NCBDDD/sicklecell/data.html. Accessed February 2013.
Martin, L. (2016 January 31, Updated). Hemoglobin electrophoresis. MedlinePlus Encyclopedia. Available online at https://medlineplus.gov/ency/article/003639.htm. Accessed on 02/18/17.
Agarwal, A. et. al. (2017 February Updated). Hemoglobinopathies. ARUP Consult. Available online at https://arupconsult.com/content/hemoglobinopathies. Accessed on 02/18/17.
Maakaron, J. et. al. (2016 September 24, Updated). Anemia. Medscape Drugs and Diseases. Available online at http://emedicine.medscape.com/article/198475-overview#showall. Accessed on 02/18/17.
Inoue, S. et. al. (2016 April 12 Updated). Pediatric Chronic Anemia. Medscape Drugs and Diseases. Available online at http://emedicine.medscape.com/article/954598-overview. Accessed on 02/18/17.
(© 1995–2017). Hemoglobin Electrophoresis Cascade, Blood. Mayo Clinic Mayo Medical Laboratories. Available online at http://www.mayomedicallaboratories.com/test-catalog/Clinical+and+Interpretive/81626 Accessed on 02/18/17.
Devkota, B. (2014 January 16 Updated). Hemoglobin Electrophoresis. Medscape Drugs and Diseases. Available online at http://emedicine.medscape.com/article/2085637-overview#showall. Accessed on 02/18/17.
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