Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) mevalonate kinase deficiency ?
    ### Response:
    Mevalonate kinase deficiency is a condition characterized by recurrent episodes of fever, which typically begin during infancy. Each episode of fever lasts about 3 to 6 days, and the frequency of the episodes varies among affected individuals. In childhood the fevers seem to be more frequent, occurring as often as 25 times a year, but as the individual gets older the episodes occur less often.
    