Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) spinocerebellar ataxia type 3 ?
    ### Response:
    Spinocerebellar ataxia type 3 (SCA3) is a condition characterized by progressive problems with movement. People with this condition initially experience problems with coordination and balance (ataxia). Other early signs and symptoms of SCA3 include speech difficulties, uncontrolled muscle tensing (dystonia), muscle stiffness (spasticity), rigidity, tremors, bulging eyes, and double vision.
    