Tests and diagnosisBy Mayo Clinic staff
Most children with moderate to severe thalassemia show signs and symptoms within their first two years of life. If your doctor suspects your child has thalassemia, he or she may confirm a diagnosis using blood tests.
If your child has thalassemia, blood tests may reveal:
- A low level of red blood cells
- Smaller than expected red blood cells
- Pale red blood cells
- Red blood cells that are varied in size and shape
- Red blood cells with uneven hemoglobin distribution, which gives the cells a bull's-eye appearance under the microscope
Blood tests may also be used to:
- Measure the amount of iron in your child's blood
- Evaluate his or her hemoglobin
- Perform DNA analysis to diagnose thalassemia or to determine if a person is carrying mutated hemoglobin genes
Testing can be done before a baby is born to find out if it has thalassemia and determine how severe it may be. Tests used to diagnose thalassemia in fetuses include:
- Chorionic villus sampling. This test is usually done around the 11th week of pregnancy and involves removing a tiny piece of the placenta for evaluation.
- Amniocentesis. This test is usually done around the 16th week of pregnancy and involves taking a sample of the fluid that surrounds the fetus.
Assisted reproductive technology
A form of assisted reproductive technology that combines pre-implantation genetic diagnosis with in vitro fertilization may help parents who have thalassemia or who are carriers of a defective hemoglobin gene give birth to healthy babies. The procedure involves retrieving mature eggs from a woman and fertilizing them with a man's sperm in a dish in a laboratory. The embryos are tested for the defective genes, and only those without genetic defects are implanted in the woman.
- What are thalassemias? National Heart, Lung, and Blood Institute. http://www.nhlbi.nih.gov/health/dci/Diseases/Thalassemia/Thalassemia_All.html. Accessed Dec. 30, 2010.
- Giardina PJ, et al. Thalessemia syndromes. In: Hoffman R, et al. Hematology: Basic Principles and Practice. 5th ed. Philadelphia, Pa.: Churchill Livingstone Elsevier; 2009. http://www.mdconsult.com/books/about.do?about=true&eid=4-u1.0-B978-0-443-06715-0..X5001-8--TOP&isbn=978-0-443-06715-0&uniqId=230100505-56. Accessed Dec. 30, 2010.
- Mueller BU. Prenatal testing for the hemoglobinopathies and thalassemias. http://www.uptodate.com/home/index.html. Accessed Jan. 3, 2011.