How common is it for somebody to get thalassemia?

Thalassemia: It is not very common, but is seen more in certain ethnic groups.

Trait is more common: The thalassemia trait is a fairly common finding in certain ethnic groups (those of mediterranean, african, and some Asian descents). The trait is generally a mild condition the contributes to a mild form of anemia that generally does not cause any problems. If both genes are affected, a child will have thalassemia which causes a much more significant type of anemia. That condition is more rare.