Epigenetic can be viewed as the mechanisms of temporal and spatial control of gene activity during the development of complex organisms. It refers to phenotype (or gene appearance) that involves modification of gene expression without involving any change of DNA sequences and these changes remain through cell divisions and are passed to future generations.
Various environmental factors are known to cause such epignetic alteration of gene expression. These even include factors of a psychological nature such as acute and chronic stress.
Epigenetic modifications in autism consistitute the most complete and compelling model that could explain the many intricate gene-environment interactions and account for the specific developmental and behavioural features of autism, including regressive autism. It is also consistent with the benefits seen with interventions such as high doses of methyl-cobalamin (vitamin B12) and methyl-rich supplements such as folinic acid, DMG & TMG (di-methyl glycine and tri-methyl-glycine).
The Presentation by Dr. Janine M. LaSalle, Professor, Department of Medical Microbiology & Immunology, University of California, Davis explains well why this model is very complelling. Please skip the first 10 min.
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SM, I had to respond to your comment on Mitchell's Gadfly blog because he has banned me.
ReplyDeleteRe regression - a couple of years ago a Dr Thomas Good was on John Best's blog, and suggested the regression was a representation of a sensory overload. I've adopted that theory because it makes a lot of sense. For it to happen though there has to be the genetic base for it. It is very easy for the untrained eye to pick up Autistic traits at their most basic (ie mild Aspergers). Even the best parents can miss it.
Sensory overload can come from any of the five senses, plus the sixth (instinct). It is hugely varied.
Timelord, thanks for your comment. I intend writing up something on regression in autism shortly, so perhaps you might want to comment further at that stage.
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