Sickle Cell Test
A sickle cell test is a blood test done to
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 screen 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,
genetic test may be done.
disease is an
autosomal recessive disease. This means that to have
the disease, a person must inherit a
gene for the disease from both parents. Each person
inherits two genes (one from each parent). As a result, a person may
- Two genes that make normal hemoglobin
(hemoglobin A). These people have normal red blood cells, unless they have some
- One gene that makes hemoglobin A and one that makes
hemoglobin S. These people carry the sickle cell trait (and are called "a
carrier"), but they do not have sickle cell disease.
Sickle cell trait is usually a harmless condition.
- Two genes that
make hemoglobin S. These people have sickle cell disease. Both parents either
carry the sickle cell trait or have the disease. Sickled red blood cells often
cause recurring health problems called
sickle cell crises.
- One gene that makes
hemoglobin S and one that makes some other abnormal type of hemoglobin.
Depending on the other type of abnormal hemoglobin, these people may have mild
sickle cell disorder.
United States Preventive Services Task Force
recommends that all newborns be tested for sickle cell disease.1
Why It Is Done
A sickle cell test screens for sickle
cell trait or sickle cell disease in 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.
How To Prepare
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.