Information on Hyperlexia
Hyperlexia is the precocious ability to read, usually before the age of 5. It is normally associated with forms of autism, and most people with hyperlexia have a visual, gestaltic reading style (i.e. they tend to read by how words look rather than sound, and they also tend to read whole words and/or phrases at once rather than break them down). NLD people, you can guess, aren't very likely to do this. However, I have read that there are 2 types of hyperlexia: this type, and a type where the individual has poor visio-spatial skills and reads phonetically.
This article discusses the two types of hyperlexia, and specifically mentions NLD.