Came across this image with the following caption
"R.J. Mitte is a good actor, but this sort of thing makes me fear that he will be typecast as 'breakfast guy'."
I didn't know he really had cerebral palsy, but I did wonder if that might be the case when I was watching the first season.
Found the following mentioned on his wiki page.
Like his character on Breaking Bad, Mitte has mild cerebral palsy. After moving to Hollywood in 2006, he began training with personal talent manager Addison Witt. Mitte and Witt sought out acting opportunities where his disability would serve to educate viewers, which led him to audition for the role in Breaking Bad.
The Screen Actors Guild named Mitte as the spokesman for actors with disabilities. He is the representative of "Inclusion in the Arts and Media of Performers with Disabilities", which employs artists with disabilities.
Although Mitte had to learn to use crutches and slur his speech for his Breaking Bad role, he continues physical and occupational therapy daily in real life to overcome the cerebral palsy he was born with. Mitte spent 13 hours a day on the set, which left no time to attend regular high school; however, the production companies Sony and AMC provided a tutor to help with his high school education."