Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Pontocerebellar hypoplasia type 1 ?
    ### Response:
    Pontocerebellar hypoplasia type 1 (PCH1) is a genetic condition that affects the development of the brain. Individuals with this condition have an unusually small and underdeveloped cerebellum, which is the part of the brain that coordinates movement. A region of the brain called the pons also fails to develop properly.
    