Genetic Dreams, Genetic Nightmares - Episode 3

CRISPR is the latest and most powerful technique for changing the
genetic code of living things. This method of gene editing is
already showing great promise in treating people with gene-based
diseases, from sickle cell disease to cancer. However, in 2018
the use of CRISPR to edit the genes of two human embryos, which
were subsequently born as two girls in China, caused outrage. The
experiment was done in secrecy and created unintended changes to
the children's genomes - changes that could be inherited by their
children and their children's children. The scandal underlined
the grave safety and ethical concerns around heritable genome
editing, and called into doubt the ability of the scientific
community to self-regulate this use of CRISPR.


CRISPR gene editing might also be used to rapidly and permanently
alter populations of organisms in the wild, and indeed perhaps
whole ecosystems, through a technique called a gene drive. A gene
drive is a way of biasing inheritance, of getting a gene (even a
deleterious one) to rapidly multiply and copy itself generation
after generation, sweeping exponentially through a population.


In theory, this could be used to eradicate species such as
agricultural pests or disease-transmitting mosquitoes, or to
alter them in some way: for example, making mosquitoes unable to
carry the malaria parasite. But do we know enough about the
consequences of releasing a self-perpetuating genetic technology
like this into the environment, even if gene drives could, for
example, eradicate insects that spread a disease which claims
hundreds of thousands of deaths every year? And who should decide
whether gene drives should be released?


First broadcast on Tuesday 3rd August 2021.