Below is an instruction from Human. Write a response.
    ### Instruction:
    How to diagnose Greig cephalopolysyndactyly syndrome ?
    ### Response:
    Is genetic testing available for Greig cephalopolysyndactyly syndrome? Yes. GLI3 is the only gene known to be associated with Greig cephalopolysyndactyly syndrome (GCPS). Genetic testing is available to analyze the GLI3 gene for mutations. Mutations involving GLI3 can be identified in greater than 75% of people with GCPS.
    