[adinisom]

They can definitely be distinct languages as is the case with protactile. For the deaf-blind people I've met, ASL is their first language and protactile is more of a second. Maybe it's different in other areas of the world.

What I've noticed is that in deaf-blind contexts plain ASL is terrible for back-channeling information... is the listener paying attention? Agreeing? Disagreeing? Laughing? Protactile communicates these back to the signer using touch, and not touching is considered rude.