Congenital diseases - Thalassemia

Congenital diseases - Thalassemia

Thalassemia is a genetic condition found in families that varies in severity. There are 4 genes called alpha chain genes and the more of these genes that are damaged or fail to function, the more apparent this condition is.
With the loss of one gene, the production of alpha protein is only diminished slightly with the result that the condition is so trivial, it is virtually unnoticeable except through extensive laboratory testing.
When 2 gene depletion or damage occurs, it will result at most in a mild form of anemia.
With the loss of three genes the result is severe anemia and individuals suffering from this condition often require blood transfusions as a result of accumulation of an abnormal hemoglobin called hemoglobin H which does not carry oxygen efficiently and causes the red blood cell containing this abnormal hemoglobin to be die prematurely.
When all four alpha genes are affected, those individuals usually die prior to birth or shortly after due to severe blood cell abnormality.