Below is an instruction from Human. Write a response.
    ### Instruction:
    What are the genetic changes related to Costello syndrome ?
    ### Response:
    Mutations in the HRAS gene cause Costello syndrome. This gene provides instructions for making a protein called H-Ras, which is part of a pathway that helps control cell growth and division. Mutations that cause Costello syndrome lead to the production of an H-Ras protein that is abnormally turned on (active).
    