Lorenzo's Oil

Lorenzo's Oil is a movie starring Nick Nolte, Susan Sarandon, and Peter Ustinov. A boy develops a disease so rare that nobody is working on a cure, so his father decides to learn all about it and tackle the problem himself.
Augusto and Michaela Odone are dealt a cruel blow by fate when their five-year-old son Lorenzo is diagnosed with a rare and incurable disease. But the Odones' persistence and faith leads to an unorthodox cure which saves their boy and re-writes medical history.