With regards to hydroxyurea, I know this is a med. that folks with sickle cell often see results with.
I only know of one or two people who have had positive results with hydroxyurea who had thal MAJOR. By this I mean they were able to spread their transfusions out to maybe 5 weeks instead of 3. It is not a cure for thal major!
In addition, the hematologist will need to see if the child is making feta hemoglobin.
One more thing, I believe you need to be willing to allow your child's hemoglobin to fall well belong recommended ranges to see if the hydroxyurea will work. (Personally, I would not be doing this experiment on a 16 month old child who can receive regular transfusions.) The friends of mine who did do a trial of hydroxyurea had children between 4 and 7 and needed to have their child's hemoglobin fall far below the 9-10 threshold...
Nicole