China has recently condemned its 'baby gene editing' scientist He Jiankui of violating both ethics and laws in his research.
The issue has forced researchers everywhere to take a hard look at the ethics of gene-editing.
What was He Jiankui's claim?
Human germline modification means deliberately changing the genes passed on to children and future generations.
He Jiankui claims to have created the world's first genetically edited babies last year. Click here to know more.
He claims to have altered twin girls' genes so they could not get HIV.
He faced severe condemnation as any application of gene editing on human embryos for reproductive purposes was unethical.
He had also allegedly used technology of an uncertain safety level.
Why is He's exercise so significant?
The promises of gene-editing using the Crispr-Cas9 editing system are boundless.
Editing DNA to correct disease mutations has been possible for a while now, which means others can also do what Mr. He did.
Over a dozen clinical trials are currently on to treat diseases like HIV, multiple myeloma and other forms of cancer.
But, notably, none of them involve editing the so-called 'human germ-line'.
Instead, they have restricted themselves to fixing genetic flaws in sick adults.
But Mr. He deactivated a gene in two human embryos, which means that the changes he made could be inherited by the next generation.
In doing so, he violated the widely held ethical consensus that it is too early for germ-line editing, as less is known on the risks associated.
What is the need for caution?
Editing the ‘human germline’ is an exercise fraught with unknown risks and embryo gene-editing is not as precise as is needed today.
The technology can result in unintended mutations, which in turn can cause cancers.
There is also the danger of mosaicism, in which some cells inherit the target mutation, while others do not.
Even when gene-editing becomes fool-proof, the decision to edit embryos will have to be assessed on its other ethical aspects.
This is because, today, there is less understanding on how exactly individual genes influence phenotypes (the visible traits of people).
Every gene likely influences multiple traits, depending on the environment it interacts with.
This makes it hard to predict the ultimate outcome of an embryo-editing exercise without decades of follow-up.
E.g. in He’s experiment, he sought to immunise a pair of twins from HIV by tinkering with a gene called CCR5
But while protecting against HIV, a deactivated CCR5 gene can also make people more susceptible to West-Nile Fever.
So in all, there is now a global need for clear guidelines on genetic intervention which can be made defensible only in very rare situations where no alternative exists.
