I think it would be comparable to situation where all mRNA is suddenly unusable, ie protein synthesis can’t run at all. This would be something like ricin or diphteria toxin poisoning, but instead of being limited to gastrointestinal lining it’s spread all over. I’d guess hours to days before anything visible starts happening (symptoms only start to appear when deficit in new protein synthesis becomes noticeable; all protein already made continues to work for sone time)