Sickledex; Hgb S test
“A blood sample is needed. For information on how this is done, see: Venipuncture
When the needle is inserted to draw blood, some people feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing.
This test is done to tell if you have abnormal hemoglobin that causes sickle cell disease and sickle cell trait.
In sickle cell disease, a person has two abnormal hemoglobin S genes. A person with sickle cell trait has only one of these abnormal genes and no symptoms, or only mild ones.
This test does not tell the difference between these two conditions. Another test, called hemoglobin electrophoresis, will be done.
A negative test result is normal.
Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.
Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.
Other risks associated with having blood drawn are slight but may include:
Iron deficiency or blood transfusions within the past 3 months can cause a false negative result.
Saunthararajah Y, Vichinsky EP. Sickle cell disease – clinical features and management. In: Hoffman R, Benz EJ, Shattil SS, et al, eds. Hematology: Basic Principles and Practice. 5th ed. Philadelphia, Pa: Elsevier Churchill Livingstone; 2008:chap 43.
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