Dominick and Eugene (1988)

Synopsis
Dominick Luciano (Thomas Hulce) is the moderately retarded twin brother of highly intelligent young intern Eugene (Ray Liotta). Anxious to become a successful doctor, Eugene finds he must devote most of his time to caring for Dominick. For his part, Dominick has been contributing to the family unit as a trash collector; in fact, it is his earnings that keeps food on the table. All Dominick wants out of life is a house by the lake where he and his brother can be together for all time. But the ambitious Eugene can't always bring himself to share that vision. ~ Hal Erickson, All Movie Guide