We are not yet Ready for Superbabies

The discourse on genetically modified babies once again rose as the CRISPR-Cas9 Technology won the Nobel Prize 2020 for Chemistry on October 7. Despite the success of CRISPR-Cas9 technology in removing unwanted DNA in test trials involving bacteria, plants, and animals, scientists are still too far from safely engineering the genetics of human embryos wherein the gene-editing technology could offer more harm than a fix to the embryos.

CRISPR-Cas9 technology prompting chaos in gene editing of human embryos. FROM: The Scientist

HOW CRISPR-Cas9 WORKS

An enzyme called Cas9, originally observed in bacteria, is responsible for cutting DNA at a targeted location. Using RNA molecules namely CRISPR RNA (cRNA) and trans-activating cRNA (tracrRNA) which are synthesized in the laboratory, the enzyme cleaves the DNA at the targeted location where the unwanted DNA is placed. The RNA molecules serve as the “guide” directing the Cas9 enzyme to the target DNA. Once the unwanted DNA is removed, the cells repair the break in the sequence using available DNA. If no other DNA material is available, cells either join the two cut ends, which can disrupt the function of the gene, or a new gene is injected to replace the deleted DNA and repair the sequence.

The CRISPR-Cas 9 and the RNA are injected into the donor DNA. In most experiments, cells grown in Petri dishes, and mouse embryos were used as donor DNA and observed under a microscope. Since its discovery in 2012, numerous researches from yeast to cows have reported success in gene-editing using CRISPR technology.

RISKS TO ABNORMALITIES

Mishaps on a newly developed genetic editing would not be surprising at all. Deletion of DNA results in chromosomal loss which can develop into Mosaicism. Mosaicism is a condition described with possession of two or more genetically different sets of cells. This condition can cause genetic disorders such as Klinefelter syndrome, Klippel-Trenaunay syndrome, Mosaic Down Syndrome, Turner syndrome, etc.

Aside from the chromosomal loss, off-target edits or unintended genetic modification in one of the regions of a human’s genome could also occur. This could lead to multiple genetic mutations that we are unfamiliar with and thus, treating diseases caused by these foreign genetic mutations would be more difficult.

INSUFFICIENT LABORATORY RESEARCHES

Even though research on CRISPR technology presents success in plants and some animals, scientists are not ready to proceed with clinical trials for human embryos gene modification. Clinical trials using CRISPR technology to combat cancer cells and other diseases have just started. One of the first clinical trials, led by researchers at the University of Pennsylvania, utilized CRISPR technology to boost cancer-fighting immune cells called T cells and were participated by three volunteers, of which two possess multiple myeloma and one with sarcoma. Although after 9 months since the experiment was conducted and the three patients experienced no harmful side effects, the progression of their cancer did not slow down. Scientists still lack sufficient data and research that could support the effectiveness of the CRISPR method and thus would be unsafe to experiment with a human embryo who could grow and live with genetic abnormalities and anomalies caused by the CRISPR method.

Another group of researchers at Columbia University experimented with 40 embryos from healthy egg donors and a sperm donor who has a gene mutation causing blindness. The aim of the research was to fix the aforementioned gene mutation, however, results show loss of the chromosome carrying the mutation.

“If our results had been known two years ago, I doubt that anyone would have gone ahead,” said Dieter Egli, a biologist leading the research who also agrees that safe gene-editing in embryos is still far.

ETHICAL REVIEW and FUTURE OF GENE MODIFICATION

The ethics of this whole process however is still being debated. While it can be used to treat genetic disorders, it can also be possible to edit the physical characteristics of a child. This wide range of possibilities can be discriminatory against those individuals with genetic characteristics that may not necessarily be life-threatening. With this technology, the eye color, skin color, or hair type and color can easily be edited, and an improved memory recall or an ideal skeletal-muscular frame for athleticism can easily be granted to a child. Doing so can be interpreted as infringing the human rights of the baby who cannot yet make decisions based on their own free will.

The ability to manipulate the genetic code of human embryos is especially promising in disease control and prenatal diagnosis, but this ability is coupled with social and ethical repercussions that can reflect well into the future. Ultimately, the concept of designer babies is proof of the potential of CRISPR-Cas9 in medicine and scientific research, but the ethics of the whole process still remain unaddressed.