Autism and learning disabilities connected to APC protein
Posted Aug 25 2010 2:22am
‘What the hell does that mean?’ I hear you cry.
OK, so the way I understand it, APC is a protien which plays an important role in helping synapses grow properly. If synapses – which are the bits that transfer data from neuron to neuron – don’t grow properly then data doesn’t get passed properly. This particular protien – APC - is responsible for the synapse function for learning and memory.
In the in vivo study, the team blocked APC function and found that synaptic levels of the cell adhesion proteins neuroligin and neurexin dropped considerably. Without normal levels of these proteins, synapses were less mature both structurally and functionally. Mutations in the genes for neuroligin and neurexin are associated with autism in humans, but until now, little was known about the mechanisms responsible for localizing these proteins at the synapse. “Our laboratory study is the first to show that APC is needed to recruit neuroligin and neurexin to the synapse. This finding provides new insights into the mechanisms required for proper synapse function as well as molecular changes at the synapse that likely contribute to autistic behaviors and learning deficits in people with APC loss of function gene mutations,” said [lead author, Michele H. ] Jacob .
Right, so – again as I understand it – when the authors blocked APC function , they found that levels of the proteins neuroligin and neurexin dropped. So what…? Well, without these two proteins at normal levels, synapses grew improperly. So what…? Turns out that scientists already know that mutuations in the genes for neuroligin and neurexin are associated with autism. Aha.
There's been a lot about intellectual disability and autism and whether they are related. This article as described here- I have yet to read it- is more proof that ID is a common, but not universal symptom of autism. This is not to say that everyone with intellectual disability is autistic, but that the processes which lead to autism very often lead to intellectual disability as well. My theory is that those who suffer from the autism related ID, have had more of their synapses affected. In other words their autism is indeed more severe.
Hi Kev -
A recent review of the participation problematic synapses and neurologic disease can be found here.
It just goes to show you how much we have to learn.