Gene editing is an incredibly promising technology for curing genetic disorders and complex diseases, yet because it is so invasive, has caused a lot of controversy. Gene editing technologies emerged in the late 1900s and involve the insertion, deletion, or replacement of specific genetic sequences. They are currently used to enhance crops and research genetics and disease in cells and animal models, but the most promising application of this technology is curing disorders with genetic components.

The greatest breakthrough in gene editing technology was the CRISPR-Cas9 system. Discovered in 2009 by Emmanuelle Charpentier, Jennifer Doudna, and Feng Zhang, this technique is faster, cheaper, and more accurate than previous techniques. It utilizes components found in bacteria, called CRISPR, and guides RNAs to precisely recognize specific DNA sequences and guide a protein structure called Cas-9 to it. There, Cas-9 can delete, insert, or replace parts of DNA sequences as desired. 

Currently, this technology has many positive implications for curing disease. In 2021, a company called Editas Medicine conducted one of the first human trials using CRISPR-Cas9 technology. They treated a rare hereditary blindness called Leber Congenital Amaurosis (LCA) via an injection into the retina that contained CRISPR-Cas9 components. The company conducted human clinical trials and found that 8 out of 14 patients had improved vision-related quality of life after the treatment and none of the patients were found to exhibit adverse outcomes due to the treatment. Many companies developing similar treatments have already conducted human clinical trials and have found positive outcomes for patients without severe side effects. 

Despite its potential, gene editing remains a complex and controversial topic in the scientific community. Gene editing technology has great potential to improve and save countless lives. However, there are many factors to consider regarding the ethics and complexity of gene editing, including technical barriers, long-term risks for children, and a lack of guidelines and laws to ensure ethical conduct. 

To understand the discussions about gene editing, it is important to distinguish somatic and germ-line cells. Somatic cells make up tissues in a developed human and cannot be inherited by future generations. Germ line cells are involved in reproduction including eggs, sperm, and cells involved in the initial stages of reproduction. These cells can be passed on to multiple generations and the long-term effects remain unknown. Current therapies to treat genetic disorders are only applied to somatic cells.

A major concern is the possibility of inaccuracy of gene editing technologies, potentially resulting in the alteration of the wrong sequence. Since editing genes have very significant physical effects on a patient, the treatment used must be precise and accurate, otherwise, genetic editing therapies can have major harmful side effects. 

One of the greatest ethical concerns is about conducting gene editing in germ-line cells. In 2018, Dr. He Jiankui conducted an extremely controversial experiment on embryos in which he edited a gene that would make them immune to HIV and two of them became living babies. His experiment sparked many discussions in the scientific community about scientific and ethical conduct in the context of genetic editing. 

Another major concern is about the line between curing devastating diseases and “enhancing” or “correcting” factors that may not need correction such as cosmetic changes. Gene editing technologies are incredibly expensive, so will scientists be able to provide these therapies to populations that are most affected by diseases, or will these therapies only benefit the wealthy? 

The scientific community continues to grapple with all of these concerns and unknowns as genetic editing becomes more relevant in the field of medicine. Despite the many promising applications of gene editing, the technical issues and ethical concerns must be addressed before it becomes a widespread method of preventing human disease.