Hmmm. I would be suspicious that the school test is really an "IQ" test. It might be some sort of aptitude test that they've created. I would be especially curious about how they got age-normed national percentile ranks if it's a test of their own. Was your DS administered the test individually, or in a group? From my very limited understanding of the common IQ tests, you must be qualified to give them (e.g., be a psychologist with specialized training).
Is there any other opportunity for your DS to get into the GT program, or do they only test in K? What would be the benefit of the GT program (what would you be fighting for, and would it be enough anyway)? Is he not getting his educational needs met? I guess I'd work from that angle first. (I.e., if your son needs more challenge, will the school respond and give appropriate work, regardless of whether your DS is ID'd as GT.)
