Thalassemia is a blood disorder passed down through families (inherited) in which the body makes an abnormal form of hemoglobin. Hemoglobin is the protein in red blood cells that carries oxygen. The disorder results in large numbers of red blood cells being destroyed, which leads to anemia.
Hemoglobin is made of two proteins: Alpha globin and beta globin. Thalassemia occurs when there is a defect in a gene that helps control production of one of these proteins.
There are two main types of thalassemia:
- Alpha thalassemia occurs when a gene or genes related to the alpha globin protein are missing or changed (mutated).
- Beta thalassemia occurs when similar gene defects affect production of the beta globin protein.
Alpha thalassemias occur most often in persons from Southeast Asia, the Middle East, China, and in those of African descent.
Beta thalassemias occur most often in persons of Mediterranean origin. To a lesser extent, Chinese, other Asians, and African Americans can be affected.
There are many forms of thalassemia. Each type has many different subtypes. Both alpha and beta thalassemia include the following two forms:
- Thalassemia major
- Thalassemia minor
You must inherit the gene defect from both parents to develop thalassemia major.
Thalassemia minor occurs if you receive the faulty gene from only one parent. Persons with this form of the disorder are carriers of the disease. Most of the time, they do not have symptoms.
Beta thalassemia major is also called Cooley's anemia.
Risk factors for thalassemia include:
- Asian, Chinese, Mediterranean, or African American ethnicity
- Family history of the disorder
The most severe form of alpha thalassemia major causes stillbirth (death of the unborn baby during birth or the late stages of pregnancy).
Children born with thalessemia major (Cooley's anemia) are normal at birth, but develop severe anemia during the first year of life.
Other symptoms can include:
Persons with the minor form of alpha and beta thalassemia have small red blood cells but no symptoms.
Exams and Tests
Your doctor will do a physical exam to look for an enlarged spleen.
A blood sample will be sent to a laboratory to be tested.
- Red blood cells will appear small and abnormally shaped when looked at under a microscope.
- A complete blood count (CBC) reveals anemia.
- A test called hemoglobin electrophoresis shows the presence of an abnormal form of hemoglobin.
- A test called mutational analysis can help detect alpha thalassemia.
Treatment for thalassemia major often involves regular blood transfusions and folate supplements.
If you receive blood transfusions, you should not take iron supplements. Doing so can cause a high amount of iron to build up in the body, which can be harmful.
Persons who receive a lot of blood transfusions need a treatment called chelation therapy. This is done to remove excess iron from the body.
A bone marrow transplant may help treat the disease in some patients, especially children.
Severe thalassemia can cause early death (between ages 20 and 30) due to heart failure. Getting regular blood transfusions and therapy to remove iron from the body helps improve the outcome.
Less severe forms of thalassemia often do not shorten lifespan.
You may want to seek genetic counseling if you have a family history of the condition and are thinking of having children.
Untreated, thalassemia major leads to heart failure and liver problems. It also makes a person more likely to develop infections.
Blood transfusions can help control some symptoms, but carry a risk of side effects from too much iron.
When to Contact a Medical Professional
Call with your health care provider if:
- You or your child has symptoms of thalassemia
- You are being treated for the disorder and new symptoms develop
Mediterranean anemia; Cooley's anemia; Beta thalassemia; Alpha thalassemia
Giardina PJ, Forget BG. Thalassemia syndromes. In: Hoffman R, Benz EJ, Shattil SS, et al., eds.Hematology: Basic Principles and Practice.
DeBaun MR, Frei-Jones M, Vichinsky E. Hemoglobinopathies. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds.Nelson Textbook of Pediatrics.
Update Date 2/24/2014
Updated by: Todd Gersten, MD, Hematology/Oncology, Florida Cancer Specialists & Research Institute, Wellington, FL. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.