Below is an instruction from Human. Write a response.
    ### Instruction:
    What are the genetic changes related to glycine encephalopathy ?
    ### Response:
    Mutations in the AMT and GLDC genes cause glycine encephalopathy.  About 80 percent of cases of glycine encephalopathy result from mutations in the GLDC gene, while AMT mutations cause 10 percent to 15 percent of all cases. In a small percentage of affected individuals, the cause of this condition is unknown.
    