PBA and autism? Has anyone had experiences with uncontrollable laughing and/or crying/tics associated. If so are you also on the spectrum for autism and is this associated with autism?

By PBA I am referring to psuedobulbar affect. (AKA Pathological Laughing and Crying) It is a condition characterized of uncontrollable laughing and crying episodes for no apparent reason. My son is 7 about to be 8 and he’s developed an issue with uncontrollable laughing and blurting out at random times just in the last two years. We have an appointment to get his diagnosis for autism coming up in March, but he is Autistic. He always had verbal and vocal stimming, but the laughing is concerning because he tells me, himself, that he cannot stop himself laughing and he gets frustrated with himself because he can’t control himself laughing and he is also crying while he is laughing at times. The only thing he has told me is that it’s something funny he was thinking about at the moment that makes him blurt out laughing, it’s hard to calm him down from laughing once he starts. We need his diagnosis so we can start ABA therapy, I was just curious if anyone else has experienced this while also being on the spectrum and what you can tell me about it? Does anyone know if it is associated with ASD as a characteristic?