Below is an instruction from Human. Write a response.
    ### Instruction:
    What are the genetic changes related to hypochondroplasia ?
    ### Response:
    About 70 percent of all cases of hypochondroplasia are caused by mutations in the FGFR3 gene. This gene provides instructions for making a protein that is involved in the development and maintenance of bone and brain tissue. Although it remains unclear how FGFR3 mutations lead to the features of hypochondroplasia, researchers believe that these genetic changes cause the protein to be overly active.
    