Below is an instruction from Human. Write a response.
    ### Instruction:
    What are the genetic changes related to hyperphosphatemic familial tumoral calcinosis ?
    ### Response:
    Mutations in the FGF23, GALNT3, or KL gene cause HFTC. The proteins produced from these genes are all involved in the regulation of phosphate levels within the body (phosphate homeostasis). Among its many functions, phosphate plays a critical role in the formation and growth of bones in childhood and helps maintain bone strength in adults.
    