He sounds an awful lot like my son, whose scores are in this thread.

My son has Asperger's syndrome/NVLD, visual processing deficits, dysgraphia, and significant problems with sensory integration and rote computation. IQ scores are not adequate information in and of themselves to diagnose any of these issues, but the scatter that you see there is certainly a sign to investigate the possibility of other exceptionalities in addition to giftedness.