My child is suffering from thalassemia major & advised for a spleen removal operation after few weeks, is this normal?

Thalassemia Major. Treatment for thalassemia major often involves regular blood transfusions and folate (folic acid) supplements. If you receive blood transfusions, you should not take iron supplements. Doing so can cause a high amount of iron to build up in the body, which can be harmful. Persons who receive significant numbers of blood transfusions need a treatment called chelation therapy to remove excess iron from the body.
Depends on severity. Thalassemia is a genetic condition where the hemoglobin is missing proper hemoglobin chains, making the hemoglobin look funny, and irregular hemoglobin makes for funny looking red cells. The spleen's job is to remove deformed red cells from the blood and destroy them. So removing the spleen greatly lengthens the red cells' lives, improving the function and oxygenation process.