This would seem to add weight to the emerging hypothesis that autism may be, in fact, a neurocristopathy, i.e. a developmental problem with the highly complex neural crest cell migration patterns in the very early stages of embryonic growth, right after the formation of the spinal cord.  This could be as simple as a random genetic expression (de novo mutations have been observed in studies and may be a response to parental exposure to environmental factors), perhaps there are epigenetic factors at work, or there may be a more proximate cause related to the molecular influences present during the migration period.  The neural crest cells lay the foundation of the autonomic and peripheral nervous systems, including the gut/enteric system (noted here), adrenal and endocrine system, facial morphology, pigment cells, heart, peripheral sensory systems, and brain (including the limbic components of the threat response system), all major players in ASD dysregulation.  The wide-spread systemic effects of ASD symptomology are simply too deeply embedded in the individual's overall makeup to be retroactively induced by post-natal influences, i.e. vaccines.  There is something deeper going on and I'm betting it's in the neural crest cell migration.