Chapter 5: Gene Therapy & Pharmacogenomics

Gene Therapy & Pharmacogenomics explores the primary biochemical compounds of heredity, deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), detailing their structures and critical roles in protein synthesis through the processes of transcription and translation. The text emphasizes the significance of the Human Genome Project (HGP), which mapped the entire human genome and expanded the understanding of genetic factors in complex acquired diseases like cancer and heart disease. Gene therapy, an emerging therapeutic technique, is introduced as a method to treat or prevent illness by directly modifying human genes—either by replacing, introducing, or inactivating problematic segments. The chapter distinguishes between direct gene transfer using vectors like recombinant DNA (rDNA) or viruses, and indirect applications, such as using rDNA technology for the large-scale manufacture of biologic drugs like human insulin. Crucially, the discussion addresses the ethical and regulatory challenges inherent to gene therapy, including patient safety oversight by organizations like Health Canada's BGTD and the prohibition of germ-line therapy due to concerns over eugenics. Finally, the chapter delves into pharmacogenomics and pharmacogenetics, explaining how genetic variations, particularly single-gene polymorphisms in drug-metabolizing enzymes (such as the cytochrome system), affect a patient's response to medications. This knowledge is fundamental to achieving personalized medicine, allowing clinicians to proactively tailor drug selection and dosage based on an individual's unique genetic profile. Nurses are required to integrate these genetic principles into practice, especially when performing comprehensive three-generation family and drug histories, ensuring informed consent for testing, and maintaining strict confidentiality of genetic information.