Does my child have to inherit the same exact mutation from both parents in order to develop cystic fibrosis?

No: Cystic fibrosis has been associated with over 1500 mutations. A person does not need to have the exact same 2 mutations inherited to have the disease. A CF patient can have 2 different mutations inherited from the parents. The extent of the disease may depend on what mutations a person has, but also varies from one patient to another even with the same mutations. Other factors play a role as well.

No: You need 2 mutations to inherit cf, but they can be, and often are, 2 different mutations. The type of mutation can have an impact on the severity of the disease and the child's prognosis.