Genetic technology and medicine

Genetic technology applied to medicine involves deliberately manipulating the genetic constitution of organisms to achieve medical benefits, which includes the production of recombinant human proteins, genetic screening, and gene therapy.

Key Applications of Genetic Technology in Medicine:

• Production of Recombinant Human Proteins: Scientists can make human proteins by transferring a gene fragment from one organism to another, leveraging the universal genetic code.

  • Insulin: Human insulin was one of the earliest successes, produced by genetically modifying E. coli or yeast. Before this, insulin was extracted from animal pancreases, which could cause adverse reactions or religious/cultural objections. Genetically engineered insulin offers a reliable, continuous, and safer supply, with lower risk of infection.

  • Factor VIII: This blood clotting protein, essential for treating haemophilia, is produced by genetically modified hamster cells. Recombinant Factor VIII avoids the infection risks associated with obtaining it from donated blood.

  • Adenosine Deaminase (ADA): Recombinant ADA is used to treat severe combined immunodeficiency (SCID), an inherited disorder affecting the immune system.

  • Other Proteins: Genetic engineering also enables the production of human growth hormone and alpha-1-antitrypsin (AAT), used to treat emphysema.

• Genetic Screening: This involves analyzing a person's DNA to detect specific alleles associated with diseases.

  • Identifying Inherited Conditions: Screening can identify inherited conditions like Huntington's disease (a late-onset nervous system disorder), cystic fibrosis (affecting breathing and digestion), and sickle cell anemia. Newborn babies are often screened for cystic fibrosis to allow early treatment.

  • Carrier Identification: It can identify carriers of mutated alleles, allowing couples with a family history of a condition to make informed decisions about having children.

  • Drug Response Prediction: Screening can determine how a patient will respond to specific drugs, enabling personalized medicine. For example, screening for a mutation in the HER2 proto-oncogene helps determine if Herceptin® will be an effective breast cancer treatment.

  • Health Risk Identification: It can identify individuals with mutated alleles that increase their risk of developing certain cancers, such as those with BRCA1 or BRCA2 mutations and breast cancer. This information can guide lifestyle choices to reduce risk or allow for preventative measures like mastectomy.

  • Preimplantation Genetic Diagnosis (PGD): This technique screens embryos created by IVF for genetic disorders before implantation, reducing the chance of having a baby with the condition and potentially avoiding the need for abortion.

• Gene Therapy: This involves altering defective genes inside cells to treat genetic disorders and cancer.

  • Recessive Allele Disorders: It is more straightforward to treat conditions caused by two mutated recessive alleles by adding a working dominant allele.

  • Somatic vs. Germ Line Therapy: Somatic therapy alters body cells and doesn't affect offspring, while germ line therapy alters sex cells and affects all future generations. Germ line therapy is currently illegal in most countries due to ethical concerns.

  • SCID Treatment: Gene therapy has been successfully used to treat SCID by introducing normal ADA genes into stem cells.

  • Inherited Eye Diseases: Some inherited eye conditions, like choroideremia, have shown partial restoration of vision through gene therapy where normal alleles are injected into retinal cells.

  • Cancer Treatment: Gene therapy aims to treat cancer by providing working versions of inactivated tumor suppressor genes, though this is still in clinical trials. Gene editing, such as CRISPR-Cas9, offers potential for precise gene modification to treat diseases like cancer and HIV.

Benefits of Genetic Technology in Medicine:

• Improved Drug Production: Recombinant DNA technology allows drugs to be produced quickly, cheaply, and in large quantities, making them more affordable and accessible.

• Early Diagnosis and Prevention: Genetic screening enables early diagnosis of conditions, allowing for prompt treatment or preventative measures, which can improve life expectancy and quality of life.

• Personalized Medicine: Tailoring medicines to an individual's DNA can predict drug responses and ensure the most effective prescriptions.

• Treatment/Cure for Genetic Diseases: It offers the potential to treat or even cure previously incurable genetic disorders.

• Organ and Tissue Regeneration: Stem cells, whose division is central to genetic processes, hold promise for replacing damaged tissues and growing organs for transplantation, saving lives and improving quality of life.

Ethical, Financial, and Social Considerations:

• Animal Testing: Vaccines and monoclonal antibodies are tested on animals before humans, which raises ethical concerns for some individuals. The use of animal-based substances in vaccine production is also a point of disagreement.

• Human Testing Risks: Testing vaccines or gene therapies on humans can be risky, potentially exposing volunteers to the disease or unforeseen side effects.

• Herd Immunity Fairness: Some individuals benefit from herd immunity without accepting the risks of vaccination, which others consider unfair.

• Monoclonal Antibody Production Ethics: Animal rights issues are involved in producing the cells used for monoclonal antibodies.

• Embryonic Stem Cell Use: Obtaining stem cells from IVF embryos raises ethical concerns because it involves the destruction of an embryo that could develop into a fetus. There are fewer objections to using artificially activated unfertilized egg cells or adult stem cells, though adult stem cells have limited differentiation potential.

• Gene Therapy Risks: Concerns exist about unintended consequences, such as the overexpression of genes (producing too much protein) or causing cancer due to uncontrolled cell division if the gene is inserted into an oncogene or tumor suppressor gene. The permanence of DNA changes and unknown long-term effects, especially if passed to future generations, are also significant concerns.

• "Designer Babies": The potential for gene therapy to be used for non-medical purposes, such as selecting desired characteristics, raises fears about "designer babies," which is currently illegal.

• Financial and Accessibility Issues: New, personalized drugs and expensive genetic technologies could lead to a two-tier health service where only wealthier individuals can afford treatments. Companies owning patents on genetic engineering technologies may limit their use, impacting accessibility.

• Privacy and Discrimination: Genetic screening results could lead to discrimination by insurance companies or employers. Revealing a drug might not work for someone can also be psychologically damaging.

• Moral and Societal Values: Fundamental questions arise about human intervention with nature ("playing God") and societal responsibility in allocating resources for expensive treatments versus basic healthcare needs. The long-term impacts of genetic modifications are still largely unknown.

• Information Ownership: There is debate over who owns genetic material once removed from the body and the implications of patenting specific seeds or genetic technologies.