The twin concordance rate in autism is something like 90% for monozygotic twins and 5% for dizygotic twins. This suggests a signigicant role for genetics in the development of autism. A new study identifies one of the possible genetic contributors, a regulatory change in the MET gene. MET signaling is important in a number of tissues, which the authors suggest is support for this being a valid finding. I’m pretty convinced–there’s a replication study, and the authors don’t do any funny things with statistics to make associations appear where they shouldn’t.
Further, the variant they identify is in the promoter of the gene, and they show that, in vitro, it leads to reduced transcription factor binding and reduced transcription. This, of course, is the most presuasive evidence.
Given the hypotheses that posit epigenetic modifications in autism, it would be interesting to see what the methylation patterns are like in the region. In fact, the SNP is a C–>G change, which creates a CpG dinucleotide, a possible target for methylation.