I too have a child with Ushers (1F). We told him at age 10, though obviously it didn't really register until some years later. Please feel free to reach out to me.
I have an (adult) child with Usher Syndrome, and have lots of connections and resources that I'd be happy to share. There is a a decent amount of research going on right now. If you like, feel free to reach me at my username at gmail.
I worked there until very close to the end, and the collapse of GO/Eo provided me with a priceless instant network of friends at dozens of companies around the SF Bay Area.
I met my spouse and some of my best friends through GO/Eo, and to this day still greatly value the connections made there for my personal and professional networks. Silver linings.
I'm also an MCC alum - I worked in the Software Technology Program. My code there had a surprisingly long life - transitioning to a spin out startup and then other companies. (See gIBIS https://en.m.wikipedia.org/wiki/Compendium_(software)#Histor... ). I too learned Lisp (and Emacs!) there - two tools that have stuck with me ever since. Many of us also started to learn Japanese there.