Indeed Dr. Darold A. Treffert has recently had a journal article published which includes a Continuing Medical Education (CME) quiz on Separating ‘Autistic-like’ Behaviors from an actual Autistic Spectrum Disorder: http://www.wisconsinmedicalsociety.org/_WMS/publications/wmj/pdf/110/6/287.pdf
Treffert identifies several categories where it is important to distinguish between Autistic and non-Autistic Spectrum children who may present with Hyperlexia and/or other symptoms:
(source: http://www.wisconsinmedicalsociety.org/_WMS/publications/wmj/pdf/110/6/287.pdf)