JJ DiMeo (Micah Fowler) is no angel. He’s sarcastic; he’s a little devious; he can be rude. In other words, he’s a teenager. The first time we see him, he flips somebody off, though we have to have it explained to us, because his version of the middle finger is a flat, extended hand.

That JJ has cerebral palsy, which keeps him from speaking, as well as limits his obscene gestures, is what makes ABC’s “Speechless” distinctive. That he’s a flawed kid with a flawed family in a reasonably funny sitcom is what makes “Speechless” good, rather than simply worthy.

For the past few seasons, ABC has become a diverse neighborhood of characters and families, especially in sitcoms like “black-ish,” “Fresh Off the Boat” and “Dr. Ken.” “Speechless” extends the idea to disability, which has long been treated as the stuff of drama or melodrama.

JJ’s educational needs drive the premise of the pilot, which airs on Wednesday, but the whole family gives it life. His mother, Maya (Minnie Driver), has moved the DiMeos to the worst house in upscale Newport Beach, Calif., because it’s zoned for a school with good resources for special-needs students.