The Potential of Gene Therapy

Article by CatholicTech Intern Dominic Andres

A new genetic therapy for a rare, but serious, disease was just tested. External DNA was introduced into mice afflicted with genetically caused movement problems in an attempt to treat the underlying cause and reverse symptoms. The treatment was highly effective, and shows great promise in treating the disease even after symptom onset.

The disease being treated is Megalencephalic leukoencephalopathy with subcortical cysts (MLC). MLC has a genetic cause in at least 75% of cases. It’s also an “orphan disease,” meaning that there is no known treatment for it, and only palliative care (treatment focused on pain relief) is possible. While the condition is extremely rare, occurring only in about 1/1,000,000 people, it’s extremely serious for those who do contract it.

The cause of MLC is a dysfunctional gene in the astroglial cells of the brain. Astroglial cells work to maintain the brain, by keeping water and potassium at the proper levels. In MLC, a problematic gene in the DNA of the astroglial cells, which normally produces a protein essential to the brain’s water regulation, stops producing that protein. This causes cells to swell and certain areas of the brain to accumulate water, leading to symptoms such as motor dysfunction, seizures, and cognitive decline.

The new treatment uses a specially modified virus to introduce new DNA into the astroglial cells, providing them with the instructions necessary to synthesize the previously missing protein. The tests, which were performed on mice, indicate both that the treatment works, and that it can be effective in reversing prior damage. This latter means it could be an effective treatment almost as soon as testing is finished.

The way genetic modification works is, frankly, amazing. We take an extremely common, and normally harmful, biological process, a viral infection, and use it to our advantage. In a viral infection, even a common cold, the virus injects new DNA into your cells, trying to use them to replicate. When scientists needed a way to inject DNA into human cells to repair damage, they had the brilliant realization that a benign virus could be used to carry the new DNA into the cell. 

While genetic therapies are a still-developing and extremely complex type of treatment, they show immense promise in treating or curing diseases which were previously untreatable, such as this one. Genetic therapy does, however, face a somewhat unusual hurdle, one that not all new treatments have to overcome.

The fundamental nature of DNA makes genetic modification a frightening concept, and it can seem like humans are playing God. When you examine genetic therapies more closely, however, they’re not something to be particularly afraid of. As explained above, since cell operation is determined by DNA, broken DNA leads to problems all the way up the line. The best way to fix those problems, then, is to modify or replace the broken sections of DNA. In the end, much of gene therapy is similar to a surgery: the doctor just goes in and fixes what’s broken.

Prominent members of the Church have spoken out in favor of genetic therapy. Pope Saint John Paul II said, in an address to the Pontifical Academy for Life, that the Church “asks political leaders and scientists to promote the good of the person through scientific research…this is possible, as scientists themselves acknowledge, in therapeutic interventions on the genome of somatic cells.” The National Catholic Bioethics Center (NCBC) has also spoken regarding the potential benefits of gene therapy, stating that “Correcting mutations in the DNA to remedy a serious medical defect would certainly be desirable and permissible.” Further, the Congregation for the Doctrine of the Faith said, in 2008, that genetic modification was permissible when used to promote “the normal genetic configuration of the patient, or to counter damage caused by genetic anomalies.”

It is important to note that, as with all new technologies, genetic modification presents certain moral dangers, dangers the Church has not glossed over. Although, as was mentioned above, gene therapy is, in principle, just another medical treatment, genetic modification more broadly is not always benign. As Pope Saint John Paul II has pointed out, DNA is the foundation of human physiology, and thus of our humanity. Man is physical as well as spiritual, not only rational, but also animal. Thus modification to DNA, if instead of being corrective is intended to “improve” humanity, can be of serious ethical concern.