As of late June 2021, it was announced that researchers have effectively treated a genetic disorder inside humans using CRISPR therapy placed into patients’ bloodstreams. CRISPR is an acronym for “clustered regularly interspaced short palindromic repeats,” a naturally-occurring genome editing system in bacteria, repurposed by scientists.
The news has made shockwaves around the medical field as the technology has the potential to dramatically improve human health.
Genetic mutations account for more than 6000 human diseases. Curing these have been extremely difficult and expensive, and not all diseases are curable with even the most recent advancements within gene therapy.
Currently, there are two main ways gene therapy is conducted: somatic cell gene editing and germ-line gene editing.
Somatic cell gene editing involves editing matured cells within a human body. This kind of editing would not become hereditary, but does cure diseases for the afflicted individual. This is the only method to alter cells within a developed human body.
Germ-line gene editing involves editing cells such as sperm, eggs or embryos. This technique would allow any genetic modifications to be passed down to any future generations. This means that the editing process only needs to occur among a few independent cells, rather than trillions of cells found within an adult human.
Before the recent breakthrough in gene editing, CRISPR was used by removing affected cells from a patient, editing out the mutations in a lab and placing them back into the body to replicate. An example of this is curing sickle cell anemia through editing and infusing bone marrow cells.
The alternative method is to use a process known as Adeno Associated Virus, or AAV gene therapy. This method actually takes an artificially created virus with the “healthy” genes implanted inside, so that the virus itself infects and delivers the healthy genes to a patient’s cells. This is the current method for curing diseases such as Spinal Muscular Atrophy.
What makes this new advancement in CRISPR technology so novel is the method of deployment. This process injects CRISPR therapy directly into the bloodstream, so that it can make edits directly to the affected cells without invasive surgery or using AAV gene therapy.
The difficulty with direct CRISPR therapy inserted into the bloodstream has been attempting to figure out how CRISPR can correctly target and edit only the affected cells necessary. This new medical trial was successfully able to inject CRISPR into the patient’s bloodstream to target and edit the affected cells in their body from a genetic disorder, paving way to what could be an entirely new process to cure genetic diseases.
The ability to genetically edit human individuals is at the core of ethics within the medical industries, and, while the recent advancement is something to be celebrated, there are concerns about approaches to ethical gene editing and deploying such technology in the right hands for the right reasons.
One end of an extreme involved a scandal involving He Jiankui, a Chinese researcher who made claims of a successful birth with the first gene-edited twin girls. He has since been jailed and received international condemnation for the dangerous and unethical research experiment.
Another concern involving gene editing revolves around self-proclaimed “biohackers,” individuals without prior educational experience who perform genetic editing techniques either on themselves or on other living species, such as plants.
Both situations signify the most important question to consider with gene editing: regulation of use.
Dr. Bryan Cwik, a bioethics philosophy professor at Portland State University, spoke with Vanguard to discuss the ways scientists can approach gene editing in an ethical way.
“The first thing to ask is, which ways work best?” Cwik said. “Are there advantages or disadvantages when treating this class of disease? These are ways to think about responsible gene editing.”
Advancements in gene therapy are still extremely elementary, and cannot cure all types of genetic diseases as we currently understand them. Cwik explains that diseases with no deterministic link and complex etiologies should not be considered for this kind of research.
Deterministic link is a technical term used by the medical industry to explain the types of connections certain genes have with diseases. Spinal Muscular Atrophy is an example of a disease with a deterministic link; if an individual has a specific genome inside their cells, they will have the disease. These types of genetic disorders are ones suited for current advancements within gene therapy treatments.
Other diseases, however, have complex ways with which they might be constructed in the body, or the ways in which a disorder is afflicted within an individual, known as etiology. Schizophrenia is a prime example of a disease that has genetic roots, but has complicated factors; scientists don’t fully understand what triggers it.
These advancements mean great news for medicine and individuals who suffer from genetic disorders such as Huntington’s disease. Others still require much more research before enough can be done. If we are to advance in gene therapies, we must be extremely cautious as to how research should be continuously conducted, and who has access to tools that constitute gene therapies.