Manal,
It is kind of confusing, but there comes a point in some intermedias lives when it is an easy decision. The key word is some, I can't speak for all. When I finally found out the options (late in life for me), I debated still for some years as to what to do. If I had known how much better I would have felt, I would have gotten transfusions much earlier. But, since I didn't know that, I continued wondering as my quality of life diminished. I didn't have much help or information. There was a point when I just had to do something because my quality of life was really going downhill. Luckily then, I found the help I needed.
So, while it is not an easy decision to make, there is at least information that can help you and your son when the time comes. Three things that I think are important to look for are: health status (is he chronically sick with infections?), bone pain/changes, and activity level. Of course knowledgeable doctors have other things they look for also.
At least you know there is something that will be able to help him if and when he needs it. That's got to be reasuring, even though it is an involved treatment. But there IS something that will help immensely - healthy blood! He has a bright future ahead of him. He has an intelligent mother who knows a lot about thalassemia, and there are new, positive changes in treatment, and hopefully new research findings that will help in the future.
I don't want to make it sound like a walk in the park, but knowing that transfusions can really help if needed, is a comforting thought. My thoughts are with you, Manal, and your son. Love, Jean