Imagine having the power to genetically engineer your baby. The power to produce a child that is both supremely attractive and hyper intelligent. An offspring that has no trace of inheritable genetic diseases. Would your choice to take this opportunity be influenced if you knew that your baby would be disadvantaged if you turned it down (The Ethical Dilemma of Designer Babies | Paul Knoepfler, 2017, 03:15-05:21)? I am describing a world in which “human germline genome editing” has become the norm (Greely, 2019). 

Thanks to the new powerful Clustered Regulated Interspaced Short Palindromic Repeats (CRISPR)-Cas technology, this future is nearly here. In nature, the CRISPR-Cas system confers immunity against foreign invaders in microbes (e.g. bacteria and fungi). CRISPR refers to a stretch of DNA which is filled with many repeating DNA sequences. The function of the CRISPR region is to store information about foreign invaders (most commonly viruses). Cas is an enzyme that cuts up the DNA of foreign invaders and inserts a tiny stretch of this DNA into the CRISPR region of the microbe. The sections of DNA that are added into the CRISPR region are known as spacer regions. In the case of a new invader, a new spacer region is added. In this way, the microbial genome will be immune to future attacks by that same foreign invader (Vidyagasar, 2018). 

In the lab, the CRISPR-Cas system can be manipulated by providing the Cas enzyme with a certain guiding RNA sequence (complex formed from sgRNA and crRNA) that directs the system to induce genomic modifications at specific loci in the genome of bacteria, humans, animals and plants (Shan et. al, 2013). While the main protein being used to perform this function is the Cas9 enzyme, other similar enzymes that perform this same function, such as Cas 12A, are also being trialled (Knott & Doudna, 2018). 

An example of the power of the CRISPR-Cas technology was demonstrated on the 25th of November, 2018 when Chinese scientist He Juankui produced two non-identical twin girls from genetically edited embryos. In the case of He Juankui’s experiment, the gene editing with CRISPR occurred on two embryos that were then placed back into the uterus of the mother. The specific gene that He Juankui edited was the CCR5 gene on chromosome 3 - the goal was to delete this gene and to produce babies whose white blood cells were immune to HIV. 

As is the case with He Juankui’s experiment, most efforts so far with the CRISPR-Cas system have aimed at targeting single genes, and have particularly focused on genetic diseases (Cox, Platt & Zhang, 2015). However, it is probably easy to see how this technology could further be advanced or extrapolated to modify increasingly complex features including intelligence, attractiveness and athleticism. 

Of course there are still challenges. In the case of He Juankui’s experiment for example, some of the cells of the twins still expressed the CCR5 gene. One of the twins was even heterozygous for the gene, meaning that the CRISPR-Cas system had only succeeded in removing one of the copies of the CCR5 gene instead of both as was planned. Although no other changes in the chromosomes or gene expressions of the twins were reported, this cannot be confirmed as the information originating from China regarding the experiment is limited (Greely, 2019). 

Therefore, while the technology is here and the future is now, there are still many issues with “designer baby technology”. These limitations include, but are not limited to, deletions of large parts of the genome (due to insufficient repair mechanisms) and other side effects that influence other regions of the genome that are not meant to be targeted (Ledford, 2020). In addition to biologically founded complications, the ethical, societal and safety related implications of implementing genetic engineering on a wider scale are still in the process of being explored (Bergman, 2019). Medical professionals, politicians and laypeople must unite to explore and overcome these challenges and to fight to maintain the transparency of this process. 

Despite in some ways being in its infancy, one cannot help but imagine a future in which each embryo is meticulously chosen from a batch of potential future babies to suit the needs of a particular family. The answer of whether you yourself would choose to genetically engineer your baby or not could be very different today than in the near future.

Wivi Taalas is a student from Finland. She recently finished her BSc in Psychology and Language Sciences at University College London and is currently studying Medicine at the University of Tartu.