Not all PGx is concerned with CYP450 enzymes. There are other drug-metabolizing enzymes that show polymorphisms and can affect the way people respond to a drug. The following is a list of enzymes for which known mutations have been associated with clinical effects.
| Enzymes | Substrates (Drugs) |
| Acetylaldehyde dehydrogenase | Alcohol |
| Acetylcholinesterase | Succinylcholine |
| Alcohol dehydrogenase | Alcohol |
| Dihydropyrimidine dehydrogenase | Fluorouracil |
| CYP2C9 | Warfarin, phenytoin, losartan |
| CYP2C19 | Diazepam, omeprazole (Prilosec) |
| CYP2D6 | Many antidepressants, opioids, antiarrhythmics |
| Glucose-6-phosphate dehydrogenase | Aspirin, quinidine |
| N-acetyltransferase | Procainamide, isoniazid |
| Thioprine methyltransferase | 6-mercaptopurine |
| UDP-glucuronosyl transferase | Acetaminophen, tolbutamide, irinotecan |
