What if before the birth of a child, parents could have the option to prevent the occurrence of any hereditary disorders in their baby? Few would pass that option. But what if you could also tweak the baby's height, or improve its mental ability, or make them resistant to some diseases? That's an intriguing prospect and an ethical horror at the same time -- and it may not be as far-fetched as it seems.
Interestingly, all of this could become a reality in the future through various gene-editing techniques that allow the creation of designer babies through the introduction of desired genes in a human embryo.
Some scientists believe that modern gene editing techniques like pre-implantation genetic testing (PGD), germline engineering, CRISPR, etc have the potential to give rise to an enhanced, super-intelligent, and disease-free human population in the future. We're not quite there yet with today's technology, but it's something that seems more and more within reach with each passing year.
However, if gene editing really becomes a tool at hand, it's not hard at all to imagine it being used for more nefarious purposes -- and the prospect of eugenics still looms very close. So with this in mind, are designer babies something to look forward to, or something to fear?
What are designer babies
The process of creating a designer baby through pre-implantation genetic diagnosis (PGD) incorporates in-vitro fertilization (IVF), embryo screening, and gene editing. At first, egg cells from a female are fused with sperms from her male partner, outside the human body using in-vitro fertilization. The resulting embryo is then allowed to reach the blastocyst stage, at which it is screened to detect the presence of any undesirable genes that can cause hereditary disorders, chromosome-linked anomalies (like Harmophilia), and other diseases.
The screening stage may involve Polymerase chain reaction (PCR), a DNA amplification (and DNA replication) method that is effective for identifying single-gene disorders like Huntington’s disease, cystic fibrosis, sickle-cell anemia, etc. Whereas, in order to detect chromosomal disorders (like polyploidy, and aneuploidy) in the embryo, biotechnology experts advocate the use of Fluorescent In Situ Hybridization (FISH), which is a reliable method to find the location of a particular DNA segment on a chromosome.
After the screening, the genetic makeup of the embryo is altered using germline engineering, a molecular technique by which the genetic information present inside an embryo or germ cells (ovum or sperm) is edited either by adding new genetic material or by eliminating already existing undesirable genes, with the help of vectors. The genetically modified embryo is then transferred into the female’s uterus where it grows into a designer baby. However, due to various safety and ethical concerns germline engineering is banned in more than 40 countries at present.
CRISPR technique and Lulu-Nana controversy
Unlike traditional gene transfer methods where vectors are used to bring about changes in the genome, CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) technique uses the Cas9 enzyme to add new genes and eliminate undesirable genetic material from the genome at targeted locations. As CRISPR allows scientists to change the genetic composition of an organism directly (without any vector), it has turned out to be a cost-effective, faster, and more efficient gene transfer technique. Some researchers also believe that CRISPR is a powerful gene manipulation method, and in the future, it can play a major role in the creation of new medicines, high-yield crops, healthier livestock, etc. In humans, the use of CRISPR for gene editing purposes in somatic cells is not that controversial because the genetic changes only affect targeted tissues and organs.
However, as far as designer babies are concerned, for now, the technique is not considered safe for embryo manipulation because apart from cutting down targeted DNA segments the Cas9 enzyme has a tendency to make irreparable cuts to other parts of the genome as well. Moreover, some studies indicate that the Cas9 enzyme can also cause harmful mutations in the human genome that can even lead to cancer, but surprisingly, these safety concerns have not been able to stop everyone from performing CRISPR on the human embryo.
In November 2018, while speaking at the International Summit on Human Genome Editing, a Chinese professor by the name of He Jiankui claimed that using the CRISPR-Cas9 gene-editing technique, he engineered the birth of two HIV-immune designer babies called Lulu and Nana. Jiankui revealed that during a clinical trial, he successfully employed the CRISPR method on some couples (where the male was an HIV patient) and disabled the CCR5 gene in their unborn children.
One of the couples that participated in his experiment conceived the twins named Lulu and Nana. Jiankui suggested that the twins are immune to HIV infection, though according to some reports, the CCR5 gene was found to be unrelated to HIV.
Moreover, Jiankui’s experiment received a lot of criticism from both local and international scientific communities. First of all, the use of CRISPR for altering the genetic makeup of a human embryo was considered an action taken against the Chinese government’s guidelines for experiments related to gene modification. It simply wasn't approved. Furthermore, while performing the trial, Jiankui violated many safety and ethical standards (for example, he experimented on live subjects despite the lack of any proven research concerning the impact of the Cas9 enzyme on the human embryo). The man, who is a biophysicist and notably has no medical degree, was shunned by the medical community and was even jailed for three years by the Chinese government -- but his case showcased just how easy it is to be led astray in the designer baby debate.
There are numerous risks associated with CRISPR but some researchers are trying to limit the activity of Cas9 on the human genome so that in the future it could be easily used to modify the human embryo. A study published in Nature suggests the development of a new CRISPR technique (that uses a method called “base editing” and a mix of Cas9 and a cytidine deaminase enzyme) that is capable of bringing about changes in the genome without cutting down DNA strands.
Scientists are also working on other techniques like ZFN (zinc-finger nucleases) and TALEN (transcription activator-like effector nucleases) as well to create designer babies.
Challenges associated with the idea of designer babies?
Adam Nash (born on August 29, 2000) is hailed as the world’s first designer baby. His conception was carried out using IVF and preimplantation genetic diagnosis (PGD). He is also called the “savior sibling” because the blood from his umbilical cord was used to treat his elder sister Molly, who was suffering from Fanconi anemia (an inherited disease) at that time and required a bone-marrow transplant.
Though Adam saved the life of his sister, this was met with a lot of criticism, some researchers accusing Adam’s parents of using the child as a product. The most important argument given against the idea of designer babies is that their rise could lead to serious physical, social, and economical disparities among humans.
Suppose we are able to develop a 100% safe and flawless technique to give birth to genetically enhanced individuals, then it is likely that only a small part of the population could afford the cost of such advanced pregnancy treatment methods. Even current technologies like IVF are very costly for many families around the world.
The limited access to designer baby technology would further exacerbate unequal distribution of wealth, resources, healthcare facilities, education, etc. Normally born humans might face discrimination due to their low intelligence, or immunity levels as compared to genetically superior individuals. People could also use these techniques to eliminate features they dislike, sparking a new brand of eugenics.
In the United States, federal law prohibits the creation of gene-edited babies. Dozens of other countries have similar prohibitions -- but many others do not. This is why many scientists and bioethicists have called for a moratorium, pending a larger public debate and clear limits about what can and can't be done with these methods. A United Nations panel called for the same thing, and the Universal Declaration on Bioethics and Human Rights was signed in 2005, listing the human genome as part of the heritage of humanity, outlining rules that need to be observed to respect human dignity, human rights, and fundamental freedoms.
However, as our ability to affect the human genome becomes better and better, the debate will become more and more pressing. We need clear, definitive guidelines, or we risk turning exciting, valuable bio-tools into a dystopian manifestation of eugenics.
There's still a lot of speculation for now, but it's never been more pressing for our scientists, governments, and lawmakers, to resolve the various challenges, fears, and risks associated with designer babies so that when their era comes, we'll truly be ready.