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A sickle cell test is a blood test done to check for sickle cell trait or sickle cell disease. Sickle cell disease is an inherited blood disease that causes red blood cells to be deformed (sickle-shaped). The red blood cells deform because they contain an abnormal type of hemoglobin, called hemoglobin S, instead of the normal hemoglobin, called hemoglobin A.
Sickled blood cells are destroyed by the body faster than normal blood cells. This causes anemia. Also, sickled cells can get trapped in blood vessels and reduce or block blood flow. This can damage organs, muscles, and bones and may lead to life-threatening conditions.
The best way to check for sickle cell trait or sickle cell disease is to look at the blood using a method called high-performance liquid chromatography (HPLC). This test identifies which type of hemoglobin is present. To confirm the results of HPLC, a genetic test may be done.
A person inherits two sets of genes (one set from each parent). As a result, a person may have:
In Canada, most provinces test newborns for sickle cell disease. Talk with your doctor for more information.
A sickle cell test is done to help diagnose sickle cell disease.
A sickle cell test is also done to screen for sickle cell trait or sickle cell disease. This test may be done for all newborns and for people at high risk. Detecting sickle cell trait is important for couples who want to have children and who may be carriers of sickle cell trait.
Be sure to tell your doctor if you have had a blood transfusion in the past 4 months because it can interfere with the test results.
A health professional uses a needle to take a blood sample, usually from the arm.
During the newborn screening test, the blood sample is usually taken from your baby’s heel (called a heel stick). The test is done in the first few days after birth, as early as 24 hours after birth. The baby's heel is poked, and several drops of blood are collected.
When a blood sample is taken, you may feel nothing at all from the needle. Or you might feel a quick sting or pinch.
A brief pain, like a sting or a pinch, is usually felt when the lancet punctures the skin. Your baby may feel a little discomfort with the skin puncture.
There is very little chance of having a problem from this test. When a blood sample is taken, a small bruise may form at the site.
There is very little risk of a problem from a heel stick. Your baby may get a small bruise at the puncture site.
Normal hemoglobin is present.
Abnormal hemoglobin is present.
In babies, a sickle cell blood test may be repeated at 6 months old, or a genetic information (DNA) test may be done.
CitationsFischbach FT, Dunning MB III, eds. (2009). Manual of Laboratory and Diagnostic Tests, 8th ed. Philadelphia: Lippincott Williams and Wilkins.
Adaptation Date: 8/17/2021
Adapted By: Alberta Health Services
Adaptation Reviewed By: Alberta Health Services
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