Sorry to hear that your son didn't get into the program you thought was the best place for him. The scores are still very high and that's a good thing.
The test did give an IQ score, but the report that was given to you was listed in percentiles. Converting the GAI score to a IQ style number involves math - check this table:
http://www.medfriendly.com/standardscoretopercentileconversion.html To get a FSIQ (Full Scale IQ) they would have had to give other parts of the test, that measure Working Memory and Processing speed. So what you have is a part of an IQ measurement. The part you have is the most important to actual intellectual strength.
It's possible that your child has a much higher Working Memory and Processing Speed - in which case your child would be great at everything as far as early leaning goes, but at risk to be one of those stories you hear about early promise that never pans out. Some people, for example, are better suited to being a medial doctor, instead of a Theoretical Physicist. Is that a better life or a worse life? To me, if the life fits the kid, and uses their strengths, it's good. So it is possible to gifted, and Highly Precocious, without being High Gifted. If possible, continue the discussion with the local Gifted Coordinator and see if you can sit in on highly gifted classes to get a sense of if you child fits there.
Or the test could be just plain wrong - it happens. Some kids fit the gifted program and never score the qualifying scores. The tests only claim to be 'usually right' and not perfect.
As far as what to do instead, the first thing to do is to post or journal about what were the concerns that you saw in the first place that lead to the testing. What to do depends on what the problem is.
How are things going for your son? Is he enjoying school academically, friendships? extracurriculars?
You also need to know what is available locally - is there a program for gifted kids? Does he make the local cut off for that? What about a subject acceleration in a subject to give him a taste of challenge?
If things just aren't adding up, you might want to make an appointment with a Psychologist for private testing. It would be good on one hand, to work with a Psychologist who is respected by your district and familiar with the highly gifted program.
Best Wishes, and let us know how things go, ok?
Love and More Love,
Grinity