Fixing the Code: Genetically Engineering Your DNA to Cure Disease

For the past 20 years, scientists have been trying to cure disease by altering DNA. We examine how with CRISPR Cas-9 gene editing and the revival of gene therapy, they’re closer than ever.

For teachers
  • Read transcript
  • Producer: Jill Rosenbaum
  • Editor: Sandrine Isambert
  • Associate Producer: Meral Agish
  • Associate Producer: Olivia Katrandjian

For Educators


This 13-minute video introduces students to the historical context, scientific procedures and social controversy surrounding the emerging medical technologies of gene therapy and gene editing, including CRISPR Cas-9. Tracing the progression of discoveries and setbacks that have charted the growth of medical biotechnology in recent decades, it combines complex scientific explanation with engaging interviews of patients and researchers. Useful as a way to introduce any lesson on medical biotechnology, the video also sets up a class discussion on the varying risks and prospects of gene therapy vs. gene editing, as well as the potential ethical challenges and public fears associated with biotechnology.

Background reading

The promise of CRISPR to edit out disease-causing genes has caused a lot of excitement but it’s just the latest attempt by scientists to fix the genes that make us sick.

Over 30 years ago, another form of genetic engineering was making headlines: gene therapy, a procedure that injected healthy genes into cells to help damaged ones.

In 1990, it was first used to treat a rare genetic disorder that crippled a four-year-old girl’s immune system.

The results were striking. As the girl’s immune system improved, she was albe to go outside and eventually attend school.

That brought the gene therapy revolution alive, with hopes to cure a range of diseases like diabetes, sickle cell anemia and muscular dystrophy.

Those expectations grew as the Human Genome Project, the national effort to find and sequence all human genes, uncovered more genes that caused hereditary diseases.

But in 1999, the attempt to deliver a healthy gene into an 18-year-old boy to treat a rare liver disease went terribly wrong. His death led to a precipitous decline in the field.

Today, 20 years later, gene therapy is back. In 2017, the Food and Drug Administration approved for the first time a gene therapy treatment for a form of childhood leukemia, and again raised hopes.

Unfortunately, gene therapy doesn’t actually fix broken genes, so no one knows how long the benefits will last. That is why there is new optimism around CRISPR – as well as a sense of caution that comes with any new cutting-edge technology.

Lesson Plan 1: Biotechnology: Gene Therapy and Gene Editing

Students will learn about the tremendous potential of gene therapy and gene editing, including CRISPR Cas-9, to cure and mitigate disease, as well as the scientific and ethical challenges surrounding these approaches.

  • How researchers are pioneering the medical applications of biotechnology.
  • How gene therapy and gene editing represent different approaches to curing diseases.
  • How patients, the public and scientists are confronting the risks, complexities, and ethical challenges surrounding innovations in biotechnology.
Essential questions
  • How could CRISPR be used to cure a disease like sickle cell anemia?
  • How is gene therapy different from gene editing?
  • How are vectors used in gene therapy? How can they create problems for patients?
  • How have researchers worked to mitigate the risks posed by vectors?
  • Common Core State Standards
    • CCSS.ELA-LITERACY.RH.11-12.1:Cite specific textual evidence to support analysis of primary and secondary sources, connecting insights gained from specific details to an understanding of the text as a whole.
    • CCSS.ELA-LITERACY.RST.11-12.2:Determine the central ideas or conclusions of a text; summarize complex concepts, processes, or information presented in a text by paraphrasing them in simpler but still accurate terms.
  • Next Generation Science Standards
    • HS-LS Heredity: Inheritance and Variation of TraitsAsk questions to clarify relationships about the role of DNA and chromosomes in coding the instructions for characteristic traits passed on from parents to offspring.
  • AP Biology
    • Topic 6.8: BiotechnologySkill 1.C: Explain biological concepts in applied contexts.