Below is an instruction from Human. Write a response.
    ### Instruction:
    What are the genetic changes related to Wolf-Hirschhorn syndrome ?
    ### Response:
    Wolf-Hirschhorn syndrome is caused by a deletion of genetic material near the end of the short (p) arm of chromosome 4. This chromosomal change is sometimes written as 4p-. The size of the deletion varies among affected individuals; studies suggest that larger deletions tend to result in more severe intellectual disability and physical abnormalities than smaller deletions.
    