Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) 22q13.3 deletion syndrome ?
    ### Response:
    22q13.3 deletion syndrome, which is also commonly known as Phelan-McDermid syndrome, is a disorder caused by the loss of a small piece of chromosome 22. The deletion occurs near the end of the chromosome at a location designated q13.3.  The features of 22q13.
    