Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Gardner syndrome ?
    ### Response:
    Gardner syndrome is a form of familial adenomatous polyposis (FAP) that is characterized by multiple colorectal polyps and various types of tumors, both benign (noncancerous) and malignant (cancerous). People affected by Gardner syndrome have a high risk of developing colorectal cancer at an early age.
    