Allelic imbalance in ASD-associated gene expression

November 18, 2019
Allelic imbalance in ASD-associated gene expression

One possible explanation for the differential expressivity of autism spectrum disorder (ASD)-associated phenotypes is allele-biased gene expression. That is, an allele carrying a mutation may have a greater or lesser effect depending on the relative level of expression of that allele. Despite this theoretical possibility, there are few documented examples of allelic imbalance in ASD.

A recent study by SFARI Investigators Daniel Geschwind and Michael Gandal, and their colleagues, sheds new light on the impact of allelic imbalance in ASD. Using a set of postmortem brain tissue samples from frontal cortex and cerebellum, the authors showed that allelic imbalance in gene expression occurs less often in ASD, but when it does occur, it exhibits preferential expression of the minor allele. In other words, the allele carrying the rare mutation shows higher expression in ASD more often than is the case for neurotypical controls. This phenomenon would add to the vulnerability of the ASD brain, since a greater