Rita has been diagnosed with her2 breast cancer, and is prescribed herceptin. the approach of basing a drug-prescribing decision on the results of a single-gene test is called:

Pharmacogenetics, it is the study of role of genome in drug response and as this name implies it is combination of pharmacology and genomics ,with this test we can find the influence of acquired drug and inherited genetic variation which causes due to drugs

B Hope it helped have a nice day