Below is an instruction from Human. Write a response.
    ### Instruction:
    How to diagnose 21-hydroxylase deficiency ?
    ### Response:
    Is genetic testing for 21-hydroxylase-deficient congenital adrenal hyperplasia available? Yes. Genetic testing of 21-hydroxylase-deficient congenital adrenal hyperplasia is available. In most people with this condition, the genetic test result can be used to predict disease severity.
    