Study Watch : Association of MET in familes with Co-occuring Autism and Gastrointestinal Conditions

The March 2009 issue of Pediatrics includes a study that demonstrates a relationship between disrupted MET signaling, Autism, and gastrointestinal dysfunction:

Distinct Genetic Risk Based on Association of MET in Families With Co-occurring Autism and Gastrointestinal Conditions

The study looked at a group of 214 families containing 918 individuals from the Autism Genetics Resource Exchange (AGRE) data set in which there was DNA samples as well as gastrointestinal information available.

The authors looked at the relationship between a disruption MET signaling and co-morbid autism and GI symptoms.  What they found was that in the 28% of the individuals (275) that had both autism and GI symptoms there existed a "functional variant in the 5' promoter of the gene encoding the MET receptor typosine kinase."  Got all that?  Basically I think this means that there is a variation in part of the pathway that controls the MET signaling process and as a result there is a decrease in this MET process.

This variation is relatively common in the general population but in study it was associated (related) in the subset of individuals that had both GI issues and autism but not in the subset that only had autism.  

So the group that has both GI issues and autism tended to have this variation but the group that had autism without GI issues did not.

This MET signaling has a role in neural development and function, immune function, and gastrointestinal systems.  Does this list sounds familiar?

The authors are quick to point out in the discussion section that this is only an exploratory study and that more research is needed to verify that there really is a relationship here.  They also point out that this study is small for the type of study that it is and that it is only as good as the results from AGRE that it is based on.

So what does this mean?  

I am not completely sure of all of the nuances of what I am reading.  I believe that it is talking about a disruption of a normal process that is happening because something is interfering with the normal function of a gene - in other words it isn't necessarily a "genetic" mutation in the common usage of the word but rather a mutation in something else (epigenetic change?) that is controlling (regulating) the gene that can be passed form generation to generation.  This variation can cause issues that might result in both autism and GI problems.