Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) congenital hyperinsulinism ?
    ### Response:
    Congenital hyperinsulinism is a condition that causes individuals to have abnormally high levels of insulin, which is a hormone that helps control blood sugar levels. People with this condition have frequent episodes of low blood sugar (hypoglycemia). In infants and young children, these episodes are characterized by a lack of energy (lethargy), irritability, or difficulty feeding.
    