The alpha thalassemias are caused by a decrease in production of alpha globin chains due to a defect in one or more of the four alpha globin genes located on chromosome 16. The alpha thalassemias can be generally categorized as: Silent Carrier, Alpha Thalassemia Trait, Hemoglobin H disease, Hemoglobin H-Constant Spring, and Alpha Thalassemia major. Frequently, the diagnosis of alpha thalassemia trait in a parent is discovered after the birth of an affected child.
The most severe form of alpha thalassemia, results in fetal or newborn death. Most individuals with alpha thalassemia have milder forms of the disease, with varying degrees of anemia.
Causes of Alpha Thalassaemia
In alpha thalassaemia there is a decrease in the production of alpha globin chains due to a deletion (missing) or mutation (abnormal change) of one or more of the four alpha globin genes located on chromosome 16.
Symptoms of Alpha Thalassaemia
Alpha Plus Thalassaemia
This is very common in some ethnic groups. There are no symptoms and it usually goes unnoticed. There may be slight iron deficiency (anaemia) if the blood is tested for some reason. Sometimes people may be mistakenly diagnosed as having iron deficiency anaemia and be treated with iron medications unnecessarily. This is quite common in India
Alpha Zero Thalassaemia
There are no symptoms and you are perfectly healthy. However if both parents have alpha zero thalassaemia they have a 1 in 4 chance of having a baby who has alpha zero thalassaemia major which is incompatible with life; the baby is often born prematurely and is dead or dies shortly after birth. This is not common in India but incidence is high in Thailand, China etc.