Imagine you have a leaky roof. Every time it rains, you put out a bucket to catch the drips. This approach is reminiscent of most treatments for chronic diseases: addressing the symptoms, but not the root cause of the condition.
The treatment paradigm
Take, for instance, type-I diabetes. To survive, 1.45 million Americans must take insulin every day to maintain their blood sugar levels. While this helps patients manage their condition, it does not cure them of the autoimmune disease.
To elaborate, type-I diabetes is characterized by the immune system recognizing the insulin-producing cells in the pancreas as a foreign threat and killing them. These cells can be viewed as insulin factories, ready to supply the body with insulin after a meal. Patients with type-I diabetes have fewer insulin factories, and consequently do not produce enough insulin to reduce their blood sugar levels without insulin injections. The exact details about what causes the immune system to feel threatened by the insulin-producing cells is not fully understood. Medical researchers have linked type-I diabetes to various genetic and environmental factors including specific gene variants and exposure to viruses.
Genetic routes
To discover genetic risk factors for type-I diabetes, scientists have investigated the genome, which can be visualized as a library of information that provides instructions for our bodies to function. The genomic library contains books, called genes, that describe specific cellular processes. The essential information communicated by a gene can be written in several ways, enabling different gene variants to exist in the population. Some gene variants are statistically associated with type-I diabetes patients, leading them to be defined as genetic risk factors for the disease. However, scientists do not necessarily know if a particular genetic risk factor is sufficient to cause patients to develop the disease since individuals have approximately 3.2 million genetic differences on average.
In their quest to determine the effect of potentially damaging gene variants, scientists have utilized the Nobel Prize-winning technique known as genome editing. This tool empowers researchers to make precise edits to the information within genes like a word processor. Informed by new data points, scientists can make causal inferences that will aid in the development of better treatments for patients with specific genetic risk factors.
A path to cures
Recent advances in genome editor delivery offer the exciting possibility of not only studying the genetics underlying diseases but curing patients by directly addressing the damaging genetic variants. Using a genome editor, a one-time treatment could replace the damaging genetic variant with a functional version, transforming the lives of patients who previously had limited options. For type-I diabetes patients, this could involve editing the genes within the insulin-producing cells that result in recognition by the immune system. With their insulin factories spared, these patients could live normal lives without needing insulin injections to maintain their blood sugar levels.
While the prospect of curing genetic diseases instead of just treating them is incredibly appealing, the path to cures is complex. One of the biggest hurdles is ensuring safety and efficacy. Since genome editing involves making permanent changes to patients, rigorous testing is essential to ensure that these changes do not have unintended consequences.
Cost is another significant challenge. Genome editing technologies can be extremely expensive to develop and deliver to the correct cells within patients. Making these therapies accessible and affordable is a critical issue that scientists, policymakers, and healthcare providers will need to address.
Ethical considerations also play a crucial role in the development of genetic treatments. Editing genes raises concerns about informed consent from future generations, especially if changes are made to reproductive cells. The potential for misuse of these powerful tools, such as for non-therapeutic enhancements and designer babies, could widen socioeconomic disparities.
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