Complex sentence: Pharmacogenetics is generally regarded as the study or clinical testing of genetic variation that gives rise to differing responses to drugs, while pharmacogenomics is the broader application of genomic technologies to new drug discovery and further characterization of older drugs.
Split into simpler sentences: Pharmacogenetics is generally regarded as the study or clinical testing of genetic variation that gives rise to differing response to drugs. While pharmacogenomics is the broader application of genomic technologies to new drug discovery and further characterization of older drugs.