Below is an instruction from Human. Write a response.
    ### Instruction:
    What are the genetic changes related to Kleefstra syndrome ?
    ### Response:
    Kleefstra syndrome is caused by the loss of the EHMT1 gene or by mutations that disable its function. The EHMT1 gene provides instructions for making an enzyme called euchromatic histone methyltransferase 1. Histone methyltransferases are enzymes that modify proteins called histones.
    