A quick update.
My son entered a study at UC Davis and took several tests, I.Q. test, physical ability, etc. and was ahead of his age group in every category except fine motor skills. Dr. Elliot Sherr stated that he is doing so well that he should be a poster child for Rhomboencephalosynapsis.
He is still having eating issues, and is behind in weight and height, but we consider ourselves very lucky that this condition has not affected his ability to advance both physically and mentally.