Someone correct me if this is not accurate..You may want to read up on this.

There may be some advantages to testing at an early age to see more about a child's potential. I believe I read between 5 and 8 were an ideal time for testing. If it's not an finacial burden and you think your child will be ok with it I would recommend testing.

My DD7 showed some signs but I really was not sure she ranked as high as her brother. The testing was good to help her Dad understand she special needs.