What are the different types of thalassemia?
There are three main types of thalassemia (and four subtypes):
- beta thalassemia, which includes the subtypes major and intermedia
- alpha thalassemia, which include the subtypes hemoglobin H and hydrops fetalis
- thalassemia minor
All of these types and subtypes vary in symptoms and severity. The onset may also vary slightly.
Beta thalassemia
Beta thalassemia occurs when your body can’t produce beta globin. Two genes, one from each parent, are inherited to make beta globin. This type of thalassemia comes in two serious subtypes: thalassemia major (Cooley’s anemia) and thalassemia intermedia.
Thalassemia major is the most severe form of beta thalassemia. It develops when beta globin genes are missing. The symptoms of thalassemia major generally appear before a child’s second birthday. The severe anemia related to this condition can be life-threatening. Other signs and symptoms include:
- fussiness
- paleness
- frequent infections
- a poor appetite
- failure to thrive
- jaundice, which is a yellowing of the skin or the whites of the eyes
- enlarged organs
This form of thalassemia is usually so severe that it requires regular blood transfusions.
Thalassemia intermedia is a less severe form. It develops because of alterations in both beta globin genes. People with thalassemia intermedia don’t need blood transfusions.
Alpha thalassemia
Alpha thalassemia occurs when the body can’t make alpha globin. In order to make alpha globin, you need to have four genes, two from each parent.
This type of thalassemia also has two serious types: hemoglobin H disease and hydrops fetalis.
Hemoglobin H develops as when a person is missing three alpha globin genes or experiences changes in these genes. This disease can lead to bone issues. The cheeks, forehead, and jaw may all overgrow. Additionally, hemoglobin H disease can cause:
- jaundice
- an extremely enlarged spleen
- malnourishment
Hydrops fetalis is an extremely severe form of thalassemia that occurs before birth. Most individuals with this condition are either stillborn or die shortly after being born. This condition develops when all four alpha globin genes are altered or missing.
