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The alpha thalassemias are caused by a decrease in production of alpha globin chains due to a deletion or mutation of one or more of the four alpha globin genes located on chromosome 16.
Alpha Thalassemia is a blood disorder, thalassemia is not one disease but rather a group of disorders that have a single feature in common: they all have a genetic defect in the production of hemoglobin, the protein that enables red blood cells to carry oxygen.
Children with alpha-thalassemia trait do not have thalassemia disease. They have no significant health problems, with the exception of possibly being mildly anemic.
Beta thalassemia
Alpha thalassemia
Thalassemia minor
Thalassemia major
Thalassemia Symptom
There are four types of alpha thalassemia that range from mild to severe in their effect on the body.
- Silent Carrier State
- Hemoglobin Constant Spring
- Alpha Thalassemia Trait or Mild Alpha Thalassemia
- Hemoglobin H Disease
- Hemoglobin H-Constant Spring
- Homozygous Constant Spring
- Hydrops Fetalis or Alpha
Alpha thalassemia trait
Alpha thalassemia trait is characterized by two functional genes that code for the production of alpha globins [(- a /- a ) or (--/ aa )]. The two genes can either occur on the same chromosome (cis-type) or on each of the pair (trans-type).
Cis-type a -thalassemia trait tends to be found in individuals of Asian descent, while trans-type tends to run in individuals of African descent.
People with this form of alpha-thalassemia may require occasional blood transfusions during times of physical stress, like fevers or other illnesses.
In alpha thalassemia, the heterozygous state (with a single gene for alpha thalassemia) is innocuous or harmless. There are no symptoms or at most mild anemia, because there is another gene still able to make alpha chains.
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