I would agree with Kai. Until his reading is commensurate with his ability (is it in the 140s?), which would be at least within a standard deviation, the reading deficit is as severe as being more than a grade level behind would be for an NT kid. And it is very important to do remediations like TBT and LB now, while he is young, and doesn't have a huge store of memorized reading vocabulary yet.

...pronounced like the long vowel and first letter of the alphabet...