Which is true concerning thalassemia? 1. It is caused by any number of factors that result in hemolysis outside the RBC. 2. It affects certain groups of persons from specific geographical regions. 3....

Which is true concerning thalassemia?

1. It is caused by any number of factors that result in hemolysis outside the RBC.

2. It affects certain groups of persons from specific geographical regions.

3. It is a form of anemia caused by a genetic defect in RBC metabolism.

4. It is the most common of the hemolytic disorders, and there is no abnormality of the hemoglobin.