Recent Advances in Genetics: Genomes, Gene Editing and Plant-Made Medicines

Genetics is moving fast

The first human genome sequence took about 13 years and an international team of thousands. Today, a lab can sequence a person's whole genome in a day or two. A disease gene that took Toronto researchers years to find in 1989 can now be found much faster. And since 2012, scientists can edit DNA at a chosen spot almost as easily as you edit a document.

The curriculum asks you to evaluate the importance of recent advances. That means more than describing them: you need to ask who benefits, how much, what the limits are, and what it costs. This lesson gives you several advances to work with and a method for evaluating them.

Advance 1: Reading genomes

The Human Genome Project (1990 to 2003) produced the first reference sequence of the roughly 3 billion base pairs in the human genome. A completely gap-free sequence was published in 2022. Since then, sequencing has become dramatically faster and cheaper.

Why it matters: doctors can now look for the cause of a rare disease in a child's whole genome; researchers compare thousands of genomes to find genes linked to diseases; and pharmacogenomics uses genetic differences to choose medicines and doses (some people break down certain drugs much faster or slower than others).

Canadian connection: The Centre for Applied Genomics at SickKids in Toronto, directed by Stephen Scherer, has been a leader in finding copy-number variation (sections of DNA that are present in different numbers of copies in different people) and in the genetics of autism. Genome Canada, a not-for-profit organization funded by the federal government, supports large genomics projects across the country.

Advance 2: The cystic fibrosis gene, from discovery to treatment

You met this in the mutations lesson: Lap-Chee Tsui's team found the CFTR gene in Toronto in 1989. It is a good case for evaluation because we can see the whole path:

1. Discovery (1989): gene and most common mutation identified.
2. Diagnosis: DNA testing for CF and for carriers.
3. Understanding: the CFTR protein is a channel for chloride ions; the common mutation makes it fold wrongly.
4. Treatment (2010s to 2020s): CFTR modulator drugs that help the faulty protein fold and open. For many people with CF, these have greatly improved lung function.

Limits: modulators do not work for every CF mutation, they are very expensive, and access depends on public drug coverage, which has been debated in Canada. Evaluation must include these points.

Advance 3: Plant-made medicines: insulin from safflowers

Millions of people with diabetes need insulin. Since the early 1980s, human insulin has been made by genetically engineered bacteria (see the reproductive technologies lesson). In the 2000s, SemBioSys Genetics, a company in Calgary, engineered safflower plants to make human insulin in their seeds. The idea: a field of safflowers could produce large amounts of insulin cheaply, using ordinary farm equipment, which might lower costs for countries where insulin is hard to afford. Early human testing suggested the plant-made insulin worked like standard insulin, but the product never reached the market.

This is molecular farming. Evaluating it: potential benefits (low-cost production, easy scale-up), challenges (keeping engineered crops separate from food crops, meeting drug-safety rules, competing with established producers), and the lesson that a scientifically successful idea does not always become a product.

Advance 4: Gene therapy and CRISPR gene editing

Gene therapy treats disease by changing genes in a patient's cells. Early approaches used a harmless virus as a vector to carry a working copy of a gene into cells. Gene therapies for some inherited forms of blindness and for spinal muscular atrophy are now approved in several countries.

CRISPR-Cas9 is a newer and much more precise tool. Bacteria use CRISPR to recognize and cut the DNA of viruses that attack them. In 2012, Jennifer Doudna and Emmanuelle Charpentier showed it could be programmed to cut any chosen DNA sequence; they won the Nobel Prize in Chemistry in 2020. In late 2023, regulators in the United Kingdom and the United States approved the first CRISPR-based therapy (Casgevy) for sickle cell disease, and approvals for beta-thalassemia followed (UK 2023, US early 2024); Health Canada authorized it for both conditions in 2024. In this therapy, doctors edit a patient's own blood stem cells outside the body so they make a form of hemoglobin that does not sickle, then return them to the patient.

A Canadian Nobel laureate

Michael Smith, a biochemist at the University of British Columbia, shared the 1993 Nobel Prize in Chemistry for developing site-directed mutagenesis: a way to change a specific base in a gene on purpose and see what happens to the protein. It is one of the ancestors of today's gene editing.

How to evaluate an advance

Use these questions, and support each answer with evidence from reliable sources (scientific organizations, government health agencies, peer-reviewed research summaries), citing them properly:

1. What problem does it solve, and for how many people?
2. How well does it work? What is the evidence?
3. What are the limits and risks? (side effects, off-target effects, unknown long-term effects)
4. Who can access it? (cost, location, public coverage)
5. What social or ethical questions does it raise? (You'll explore these in the next lesson.)