Question: was the movie jack based on a true story

Answer: No, Jack is a 1996 American comedy-drama film starring Robin Williams and directed by Francis Ford Coppola. The film co-stars Diane Lane, Jennifer Lopez, Fran Drescher, Bill Cosby, and Brian Kerwin. Williams plays the role of Jack Powell, a boy who ages four times faster than normal as a result of Werner syndrome, a form of progeria.