Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Menkes syndrome ?
    ### Response:
    Menkes syndrome is a disorder that affects copper levels in the body. It is characterized by sparse, kinky hair; failure to gain weight and grow at the expected rate (failure to thrive); and deterioration of the nervous system. Additional signs and symptoms include weak muscle tone (hypotonia), sagging facial features, seizures, developmental delay, and intellectual disability.
    