"He can read well, but he just 'word calls'. He doesn't understand what he reads. He must have hyperlexia."
I hear this sentiment quite often from speech therapists and autism specialists. While older notions of hyperlexia looked at a difference between reading comprehension and reading ability as the basic diagnostic criteria, this criteria has several holes.
First, If a child began reading at the typical age of 5-6 and reads on an average level, but struggles with comprehension, that child is not hyperlexic ( Hyper=Early or advanced, Lexic= Reader). They are simply an average reader with a reading comprehension disorder (or simply showing a standard cognitive profile seen in a child with autism).
Secondly, this diagnostic criteria completely ignores the sub-population of early readers (ages 1-3) who, in fact, comprehend what they read (better than they comprehend spoken language).
Thirdly, it ignores the causality between global language processing and early reading. Children who are truly hyperlexic show a profile of language processing struggles and amazing early reading ability. The early reading is therefore a way to make meaning of a world when spoken language is confusing and muddled.
If a child, in fact, is not supported in their early reading ability, given the opportunity to gain important vocabulary, language structure, and communication skills through their first language (the printed word) then they will be delayed in global language comprehension, both print and spoken language.
A hyperlexic child who grows up in a print-rich environment with parents, therapists, and teachers who understand the nature of their learning style stand a greater chance of not falling into the "old" definition of hyperlexia. They may, in fact, NOT struggle with reading comprehension and just simply become amazing readers!