Below is an instruction from Human. Write a response.
    ### Instruction:
    What are the genetic changes related to catecholaminergic polymorphic ventricular tachycardia ?
    ### Response:
    CPVT can result from mutations in two genes, RYR2 and CASQ2. RYR2 gene mutations cause about half of all cases, while mutations in the CASQ2 gene account for 1 percent to 2 percent of cases. In people without an identified mutation in one of these genes, the genetic cause of the disorder is unknown.
    