Figuring out how autism starts is complicated.
…[A] large international team obtained skin cells from eight autistic people and five controls. These were converted into stem cells and then induced to develop along a pathway that leads to brain-like neurons.
..[Researchers] identified three distinct groups of genes (which they termed “modules”) that defined distinct stages of the developmental process. You can think of these stages as pre-neuron, neural stem cell, and maturing neuron.
…[W]hile normal cells might reach a given stage of gene activity at day four, those from autistic patients might reach that at day two. This accelerated pace was also apparent in the physical changes the cells undergo as they mature.
The timing of all of this suggested to the authors that the problems in these autistic individuals came from the process of forming neural stem cells.
…[T]he results do indicate that, at least in some individuals with autism, problems start extremely early. In humans, neural stem cells are specified before three weeks into the pregnancy—a point when many people aren’t even aware or certain they’re pregnant. Depending on how general this is, that may mean that interventions at the earliest stages of autism—either by directly addressing the problem or by limiting any environmental influences that promote autism—is pretty unlikely.
Read full, original post: Stem cells used to trace autism back to the formation of neurons