Below is an instruction from Human. Write a response.
    ### Instruction:
    What are the symptoms of Tay-Sachs disease ?
    ### Response:
    What are the signs and symptoms of Tay-Sachs disease? The most common form of Tay-Sachs disease begins in infancy. Infants with this disorder typically appear normal until the age of 3 to 6 months, when development slows and muscles used for movement weaken.
    