Genetic Testing Overview

Genetic Testing

• Genetic testing analyzes DNA to determine if a person carries a genetic disease or has a predisposition for one.
• Genetic testing can be used for prenatal screening, carrier screening, pre-implantation testing, and population screening.
• Carrier screening determines if someone carries a mutated gene which is different from having the disease.
• Prenatal screening tests are done during pregnancy to assess fetal health.
• Pre-implantation testing screens embryos for genetic diseases before implantation in IVF.
• Population screening looks for genetic diseases within a specific population.
• Genetic counselors help patients understand testing results and make informed decisions.
• Ethical considerations include privacy concerns and access to testing.
• Specificity measures the accuracy of a negative test whereas sensitivity measures the accuracy of a positive test.

FDA

• The FDA ensures the safety and effectiveness of drugs before they are approved for use.
• Clinical trials assess the safety and efficacy of new drugs using different phases:
  • Phase 1: safety testing in a small group of healthy individuals.
  • Phase 2: effectiveness testing in a larger group of individuals with the disease.
  • Phase 3: large-scale trials to confirm effectiveness and monitor side effects.
  • Phase 4: post-market surveillance to monitor long-term safety and effectiveness.

Gene Therapy

• Gene therapy replaces or alters mutated genes to treat diseases.
• There are two main types:
  • Somatic gene therapy targets specific cells and does not pass down to offspring.
  • Germ-line gene therapy targets reproductive cells and can be passed down to future generations.
• Somatic gene therapy can be administered through vectors like viruses or directly.
• Germ-line gene therapy faces ethical concerns due to the potential for unintended consequences.
• Vectors are used to deliver therapeutic DNA into cells.
• Gene therapy is expensive due to research and development costs.
• Gene therapy is a relatively new and evolving field.

GMO

• A GMO is an organism that has been genetically modified to alter its traits.
• Recombinant DNA involves combining DNA from different sources.
• Cloning in bacteria makes copies of a gene to produce a protein of interest.
• Transgenic organisms have genes from different species introduced into their DNA.
• Pharming uses genetically modified animals to produce pharmaceuticals.
• rBGH is a genetically modified growth hormone produced by bacteria.
• Bt gene produces a pesticide that kills insects.
• Roundup Ready soybeans produce a protein that makes them resistant to herbicides.
• Genetic modification in plants can provide benefits like increased yields, improved nutritional value, and pest resistance.
• The USDA regulates genetically modified foods in the US.

Blood

• Blood carries oxygen, nutrients, and hormones throughout the body.
• Blood is composed of:
  • Plasma: fluid component
  • Formed elements: cells (red blood cells, white blood cells, platelets)
  • Red blood cells transport oxygen, contain hemoglobin.
  • White blood cells fight infections.
  • Platelets help in clotting.
• Blood cells are produced in the bone marrow via hematopoiesis.
• Oxyhemoglobin carries oxygen, deoxyhemoglobin releases it.
• Malaria causes anemia by destroying red blood cells.
• Blood transfusions must match blood types to avoid complications.
• Rh-negative mothers may receive RhoGAM during pregnancy to prevent complications.
• Blood clots form through a complex process involving platelets and clotting factors.
• Anticoagulants are medications used to prevent blood clotting.

Cardiovascular System

• Consists of the heart and blood vessels (arteries, veins, capillaries).
• Arteries carry oxygenated blood away from the heart.
• Veins carry deoxygenated blood back to the heart.
• Capillaries facilitate nutrient and gas exchange between blood and tissues.
• Valves in veins prevent blood from flowing back.