(5.4) Medical applications of GM technology products including genetic modifications to the human genome

• (a) The production of human insulin by genetically modified bacteria (discussed in Part 5.2).

  • GM produced insulin production has been described in detail above.

  • The process overall is one of inserting the human insulin gene into bacteria and growing the bacteria to produce lots of insulin quickly and economically efficiently (cheaply!).

  • The resulting, and efficiently produced, insulin can be used to treat people with diabetes, and is an example of genetically engineering bacteria, in this case to produce human insulin.

• (b) In other medical applications, scientists have transferred human genes into cows and sheep to produce useful proteins.

  • You can 'manufacture' human antibodies used in the treatment of arthritis, multiple sclerosis and some types of cancer.

  • These useful proteins can be extracted from the 'host' animal e.g. from cows milk.

  • It might be possible in future to use animal organs grown specially for transplant operations - ethical issues!

• (c) Medical researchers are trying to develop genetic modification treatments for inherited diseases caused by faulty genes.

  • The idea is to insert correctly working genes (the normal correctly working allele) into the cells of people suffering from the disorder caused by alleles of faulty genes.

  • This technique is called gene therapy - a sort of allele replacement technique.

  • Gene therapy is at a very experimental stage, but much is hoped from this technique.

  • It is sometimes possible to transfer the 'working' gene when the organism is at an early stage of development.

    • e.g. applying gene therapy to an egg or embryo so that the organism develops with the characteristic correctly coded for by the gene - correct genotype, giving the correct phenotype.

  • However, the following description describes one particular type of gene therapy involving cell exchange.

    • An example of a gene therapy procedure

    • A deactivated virus is used as a vector, but it is quite difficult to replace genes effectively.

    • (1) A normal human allele is inserted into the virus vector - the altered virus.

    • (2) Cells carrying the defective gene are removed from the patient.

    • (3) The altered virus is inserted into the cells removed from the patient.

    • (4) The modified cells are then injected back into the patient.

    • (5) Then, hopefully, the modified cells can then carry out their function correctly.

  • Problems encountered in gene therapy patients

    • An overactive immune response, which in some early cases was lethal - the modified cells were treated as foreign pathogens by the immune system.

    • Leukaemia cases occurred, probably due to the virus vector.

  • Genome editing

    • Genome editing is emerging as a potential biotechnology involving replacing or removing sections of DNA of an animals genome.

    • It is possible to do this using 'molecular scissors' and the technique is improving all the time.

      • (As I'm writing this in 2020, two female scientists have been awarded the Nobel Prize in Chemistry for their work in developing gene editing techniques. Emmanuelle Charpentier and Jennifer A. Doudna developed the Crispr tool, which can change the DNA of animals, plants and microorganisms with high precision.)

    • Note that any successful gene therapy cannot prevent the patient from passing on an inherited medical condition to their children.

      • It is only the patient's cells that are modified.

      • Any modification of the reproductive cells (male and female gametes) involves at least two immediate problems.

      • (i) Extremely technically difficult to do,

      • (ii) and poses major ethical problems as to the right to carry out such a procedure - 'designer babies'.

      • This type of gamete gene therapy is not allowed by law.

---

Key points Source of information is based on textbooks & syllabus-specifications for students taking the AQA GCSE, Edexcel GCSE and OCR GCSE level biology examinations (~US grades 9-10).

Key points and ideas about gene editing therapies

Medical Applications of GM Technology: Gene Therapy & Gene Editing

Genetic engineering has revolutionized medicine by enabling gene therapy and gene editing to treat inherited disorders.

These technologies allow scientists to modify the human genome, correcting faulty genes and preventing genetic diseases.

---

1. What Is Gene Therapy?

Gene therapy involves inserting, modifying, or replacing defective genes to treat genetic conditions.

Types of Gene Therapy:

• Somatic Cell Gene Therapy: Alters genes in body cells but does not affect future generations.

• Germline Gene Therapy: Modifies reproductive cells (sperm or egg), affecting future generations (currently illegal in humans).

Examples of Gene Therapy Applications:

• Treating Cystic Fibrosis: Inserting functional CFTR genes into lung cells.

• Cancer Treatment: Modifying immune cells to target tumors.

• Sickle Cell Anemia Treatment: Correcting faulty hemoglobin genes.

---

2. Gene Editing and the Human Genome

Gene editing uses advanced tools to modify DNA sequences precisely.

CRISPR-Cas9: The Most Powerful Gene Editing Tool

• CRISPR-Cas9 enables scientists to cut and edit genes accurately.

• Used in correcting mutations linked to genetic disorders.

• Helps in potential cures for diseases like muscular dystrophy and Huntington’s disease.

---

3. Problems and Challenges in Gene Editing

Despite its benefits, gene editing faces scientific, ethical, and legal concerns.

Key Issues:

• Unintended Mutations: Editing may cause unexpected genetic changes, leading to health risks.

• Ethical Concerns: Modifying human genes raises questions about altering traits and designer babies.

• Long-Term Effects Unknown: Future generations may inherit unforeseen consequences.

• Cost and Accessibility: Advanced gene therapy is expensive and not widely available.

---

4. Advantages and Disadvantages of GM Medical Technology

Advantages:

• Cures Genetic Disorders: Offers potential treatments for life-threatening diseases.

• Reduces Disease Risk: Can help prevent inherited conditions.

• Improves Personalized Medicine: Tailors treatments to an individual's genetic profile.

• Enhances Research: Advances understanding of genetic functions and human evolution.

Disadvantages:

• Ethical Concerns: Issues regarding genetic manipulation and societal implications.

• Expensive & Complex: High costs limit accessibility worldwide.

• Risk of Genetic Mistakes: Errors in gene editing could cause harmful mutations.

• Legal Restrictions: Many countries ban human germline editing due to ethical risks.

---

5. Importance in Understanding Human Genetics

Studying gene therapy and editing helps scientists:

• Develop New Treatments: Finding cures for genetic diseases.

• Improve Medical Research: Enhancing knowledge in genetics and biotechnology.

• Evaluate Ethical Implications: Assessing responsible use of genetic modifications.

• Understand Evolution & Heredity: Exploring genetic variation and inheritance.

Gene therapy and gene editing mark a new era in medicine, offering groundbreaking potential while raising complex ethical and scientific challenges.

---

Summary of learning objectives and key words or phrases

Understand that gene therapy can be used to treat medical conditions.

The procedures involve gene editing in these medical applications of GM technology

Medical GM  genetic like gene therapy involve modifications to the human genome

---

WHAT NEXT?

TOP OF PAGE

INDEX of biology notes on genetics and applications of GM biotechnology

INDEX of all my BIOLOGY NOTES

BIG website, try using the [SEARCH BOX], maybe quicker than the many indexes!

Basic Science Quizzes for UK KS3 science students aged ~12-14, ~US grades 6-8

Biology * Chemistry * Physics for UK GCSE level students aged ~14-16, ~US grades 9-10

Advanced Level Chemistry for pre-university age ~16-18 ~US grades 11-12, K12 Honors

Find your GCSE/IGCSE science course for more help links to all science revision notes

email doc brown - comments - query?

---

medical applications of GM technology described for syllabus-specifications for students taking the IGCSE/GCSE level biology examinations, summary revision notes key points on medical applications of GM technology described for students studying AQA igcse/gcse biology notes on medical applications of GM technology described, Edexcel gcse biology notes on medical applications of GM technology described,  OCR 21st century GCSE biology notes on medical applications of GM technology described, OCR gateway GCSE biology notes on medical applications of GM technology described, WJEC gcse biology notes on medical applications of GM technology described, CCEA gcse biology notes on medical applications of GM technology described, CIE Cambridge igcse biology, notes on medical applications of GM technology described useful for US grade 9-10 biology student courses, Explaining importance of use of gene editing of human genome in gene therapy in GCSE level biology, What you need to know about use of gene editing of human genome in gene therapy for GCSE level biology, Explaining use of use of gene editing of human genome in gene therapy knowledge in GCSE level biology, Examples of use of gene editing of human genome in gene therapy explained when studying GCSE level biology, What is the significance of use of gene editing of human genome in gene therapy in GCSE level biology, describing explaining theory of use of gene editing of human genome in gene therapy when studying GCSE level biology, exam revision notes for use of gene editing of human genome in gene therapy, online help for understanding use of gene editing of human genome in gene therapy in GCSE biology, what do I need to learn about use of gene editing of human genome in gene therapy? what do I need to know about use of gene editing of human genome in gene therapy for GCSE biology exams, how to prepare for questions on use of gene editing of human genome in gene therapy in GCSE biology examination?

---