Below is an instruction from Human. Write a response.
    ### Instruction:
    What are the genetic changes related to 15q13.3 microdeletion ?
    ### Response:
    Most people with a 15q13.3 microdeletion are missing a sequence of about 2 million DNA building blocks (base pairs), also written as 2 megabases (Mb), at position q13.3 on chromosome 15. The exact size of the deleted region varies, but it typically contains at least six genes.
    