myrtle has leukemia and her doctor is thinking about giving her the chemotherapy drug purinethol, which is the best drug for this type of leukemia. tpmt is an enzyme that breaks down purinethol in the body so that it doesn't build up to high levels and become toxic. myrtle's doctor does a genetic test and finds out she has a version of tpmt that has extremely high activity compared to the average person. what do you expect myrtle's doctor will do?
