The essence is: We have found another protein complex (affected by other gene mutations) that disturbs the normal functioning of a nerve cell in very similar aspects as the previously found protein complex. Imagine you find that the postman has a limp and then you find that the postman's car is slow so you can argue that it is about the slowness of the mail delivery that is at the core of the problems. And that is also what Dennis suggested: at least some stuttering might be part of issues with "moving things around in the nerve cells (which can be quite long)" which are suspected causing all kinds of neurological disorders.
And I am happy to hear that they do what I asked them to do: Only brainscan people with the same mututation! This is the way forward in my view.
Of course we need to be careful:
- not all stuttering is driving by this.
- neurodevelopmental issues could affect similar areas but are driven not by gene mutation
- Dennis knows much more about but again we have to wait years until he publishes it. ;-)