Cut, Paste, Repeat: The DNA Debate

Gene editing technology allows scientists to make changes in an organism’s DNA. This newfound magic has made it possible for scientists to create cattle without horns, tomatoes that ripen slowly over time, livestock that produce high-quality meat and milk and are highly disease resistant, goats that produce milk with strong spiderweb-like silk proteins in their milk, and the list goes on.

The next leap that gene editing took was Human Gene Editing. Its potential now is undeniable, though it was mainly an opportunity to edit the disease out of the human genome. We are at the point where this technology will significantly question humanity. Scientists are now creating babies whose genetic makeup would be selected or altered to include a favourable gene or remove an undesired one. In a way, these babies are the results of years of IVF research. Once it was proven that babies could be made or created in labs, embryo editing to produce a healthy genetically modified baby was perhaps considered natural. The ‘natural’ nature of this birth would include the modification of characteristics or traits including gender, intelligence quotient, disease resistance, immunity power, personality and appearance (eye colour, height, hair colour, etc.)

There are three existing techniques involved in the production of designer babies. The first and the most basic one of all is the PGD (Pre-implantation genetic diagnosis) technique, a procedure in which embryos are screened before implantation. This technique was first put into practice in 1989. PGD is primarily used to identify embryos with genetic defects, allowing identification and correction of mutated or disease-related alleles. It is particularly beneficial to parents where one or both carry a heritable disease like haemophilia, sickle cell, etc. PGD can also be used to select embryos of a certain specific sex, most commonly when a disease is more strongly linked with one sex than the other.

The next technique, TALENs, is a prominent tool in the field of genome editing. Transcription Activator Like Effector Nucleases (TALEN) are restriction enzymes that can be engineered to cut specific sequences of DNA. Transcription activator-like effectors (TALEs) can be made to bind to practically any desired DNA sequence, so when combined with a nuclease, DNA can be cut at specific locations. Non-homologous end Joining (NHEJ) precisely ligates DNA from either side of a double-strand break where there is very little or no sequence overlap for annealing. This mechanism induces errors in the genome via indels (insertion and deletion) or chromosomal rearrangement; any such errors may render the gene products coded at that location non-functional. Since this activity can vary depending on the species, cell type, target gene and nuclease used, it should be monitored when designing new systems.

TALEN has been used to efficiently modify plant genomes, creating economically important food crops with favourable nutritional qualities. They have also been harnessed to develop tools for the production of biofuels. TALEN has additionally been utilized experimentally to correct the genetic errors that underline disease. Recently, it was shown that TALEN can be used as tools to harness the immune system to fight cancers; TALEN-mediated targeting can generate T cells that are resistant to chemotherapeutic drugs and show anti-tumour activity.

The last technique, CRISPR (Clusters of Regularly Interspaced Short Palindromic Repeats) is a simple yet powerful tool for editing genes. It allows researchers to easily alter DNA sequences and modify gene function. Its many applications include correcting genetic defects, treating and preventing the spread of diseases and improving crops. However, its promise also raises ethical concerns. CRISPR technology was adapted from the natural defence mechanisms of bacteria and archaea. These organisms use CRISPR-derived RNA and various Cas proteins to foil attacks by viruses and other foreign bodies. They do so primarily by chopping up and destroying the DNA of a foreign invader. When these components are transferred into other, more complex organisms, it allows for the modification of genes, or ‘editing. ’

He Jiankui, working at the Southern University of Science and Technology in Shenzhen, China, started a project to help people with fertility problems, particularly concerning HIV positive fathers and HIV negative mothers. The subjects then went through in vitro fertilisation and CRISPR gene editing technology for DNA modification. This clinical project was conducted secretly until 25^th November 2018, when MIT Technology Review uncovered the tale about the human experiment based on information from the Chinese clinical trials registry. Compelled by the situation, He instantly announced the birth of genome-edited babies in a series of five videos on YouTube the same day. The first babies, known by their pseudonyms Lulu and Nana, are twin girls born in October 2018. He reported that the babies were born healthy.

When it comes to the subject of designer babies, or even the thought of being able to create a ‘perfect’ child, there will surely arise both controversies and pure relief because the topic is extremely two faceted. One may state that being able to genetically modify a baby so it has no chances of coming out deformed or with any known mental or physical diseases or disabilities is a miracle, of course. The other might contradict, saying that in the law of ethics, this is not acceptable. The fact that one is choosing their child’s looks, fate and even personality is morally ‘wrong’. Furthermore, there is the possibility that people will use the technology for ‘enhancements’ rather than fighting disease. The more one has control over the ability to design one's children, the bigger the moral questions rise up to, including who decides what constitutes a genetic problem that needs to be fixed. In addition to this, Undesirable mutations introduced by gene editing to sperm, eggs or early stage embryos could be reproduced in future generations. But future generations are unable to give their consent to the risk being taken. Along with all this, one should also consider the difficulties that a designer baby would face in a considerably ‘normal’ society.  The inclusion of such ‘superior’ individuals could create a gap in society and greatly affect community living. Differences can even occur within the family, between the ‘superior’ child and the ‘normal’ ones.  

While today, the world is on the roads demanding consent for various reasons, regarding this technology, the baby has no choice in the matter, and the notion of individuality is completely lost. Scientifically speaking, one should keep in mind that a particular gene has more than one function and that while possibly altering the genes for the better, there can also occur damage to the gene pool. Now, is this a good thing or a bad thing? Either way, it’s happening. One would say that the under-examined implications are around income inequality. Will we reach a time where only poor women would have to worry about miscarriages? When rich couples never have to receive the devastating news that their foetus or baby has a chromosomal or genetic abnormality? When lower- and middle-class women will have their children in their 20s and 30s, while the rich women can even wait until after their 40s for healthy babies? And will families with children all of the same gender someday signal poverty? Are we headed for a future where those with the means will be able to purchase genetic superiority, leaving the rest of us behind? This science fiction outcome is probably less desirable than we think.