Researchers at Harvard University are suggesting a new theory of autism. They are raising the possibility that atypical neurological responses to touch can play an important role in developing symptoms of autism, and suggesting that abnormal levels of MeCP2 levels in cells that respond to touch can be critical to the development of symptoms of autism.
Experiments with a number of types of genetically engineered laboratory mice, they found autistic-like behavior developed in those without MECP2 activity in touch cells, but not if normal activity was present in touch cells but not in other cells in the body. There are a number of cautions in interpreting this finding and the associated theory, but there are also a number of general observations that make this theory enticing.
On the caution side, it is important to note that behavioural changes in mice are hard to apply directly to humans. Also, it is not necessarily true that because autistic like changes can be produced by this alteration in cell function that this alteration is the cause of all or even a significant number of cases of human autism. In regard to MECP2 duplication syndrome, it is also important to remember that this study looked at the effects of MECP2 underactivity not overactivity, suggesting the finding could be more relevant to Rett syndrome than MECP2 Duplication Syndrome. Nevertheless, the role of MECP2 as a “Goldilocks gene,” where too little and too much can produce similar outcomes, suggests that that the same or a similar effect on touch could be present. In fact, since autistic behaviours are present in both Rett and MECP2 duplication syndrome, it would likely have to be true that both overactivity and underactivity would produce this effect to explain similar behaviour in both syndromes via this touch-sensitivity theory. As a more general caution, the entire field of autism research has been flooded with amazing research findings that seemed to give answers at the time, but only raised more questions in the long run.
On the other hand, a number of observations in MECP2 duplication syndrome and autism in general make this finding seem consistent with other observations. For example, the reports that “hug-machines” and weighted blankets have been useful in autism implies that the sense of touch could be important or even critical.
So, for now, this has the potential to open a very interesting area of research in autism. In Rett syndrome and MECP2 duplication syndrome, this suggests that the sense of touch might be something that needs much closer attention in research. Most research on autism has focused on neuronal processes within the brain; This research suggests that sensory input TO the brain may play an essential role.
Orefice, LL, Zimmerman, AL, Chirila, AM, Steven J. Sleboda, SJ, Head, JP,Ginty, DD. (2016). Peripheral Mechanosensory Neuron Dysfunction Underlies Tactile and Behavioral Deficits in Mouse Models of ASDs http://dx.doi.org/10.1016/j.cell.2016.05.033