Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Progressive myoclonic epilepsy ?
    ### Response:
    Progressive myoclonus epilepsy (PME) refers to a group of inherited conditions involving the central nervous system and representing more than a dozen different diseases. These diseases share certain features, including a worsening of symptoms over time and the presence of both muscle contractions (myoclonus) and seizures (epilepsy).
    