The Ethics of Genomic Sequencing: Answers Raising Questions
Blog Apr 26, 2016
Genomic sequencing opens the door to incredible amounts of data—data that changes the way we think about both research and clinical care. Unlike genotyping, which detects a person’s particular genetic variant compared to a reference, genomic sequencing has no predefined target: the test sequences the entire genome in order, base-to-base. The information gained from genomic sequencing holds the key to medical advances but must be used responsibly.
A symptom’s origin—often a change in a gene—can be revealed through genomic sequencing. Everyone has changes in their genome, and most of these have little to no effect on a person’s health. However, some alterations to DNA can be very harmful. These detrimental changes to DNA are known as mutations. Many rare diseases are genetic disorders caused by a mutation at a crucial point in a person’s DNA.
One example is Sjogren’s Syndrome, a rare autoimmune disease that causes dryness throughout the body. White blood cells attack the exocrine glands, including the salivary and lacrimal glands that make saliva and tears. Patients with Sjogren’s syndrome show mutations in the gene regions that control the production of human leukocyte antigen, which is involved in the body’s immune response.
We can now detect diseases before symptoms even show: genetic markers for adult-onset diseases, like Huntington’s disease (HD), can be diagnosed by genomic sequencing. Symptoms from HD, a neurodegenerative genetic disorder, typically appear in middle age. Currently, HD has no cure. If a patient has genomic sequencing to address another health issue, the marker for HD could be found as an incidental finding. That is, genomic sequencing exposed an additional diagnosis unrelated to the issue that brought the patient to the clinician. Genomic sequencing can also show markers that can determine a patient’s likelihood of developing other untreatable conditions such as Alzheimer’s disease or different forms of cancer.
Imagine trying to read a book letter-by-letter. A few of the words the letters form are familiar. Most of the words, though, aren’t in your vocabulary. These unfamiliar words aren’t in the dictionary, and there isn’t enough context to guess their meaning with confidence. In the same way, even though the entire human genome can be “read” base-by-base, not all of the results make sense yet. In many cases, a patient may find that they have a genetic “variant of unknown significance.” While there is a change in that person’s DNA, the effect of this change cannot be determined due to a lack of clinical information. In order to have meaning, the discovery of a new genetic variant must be placed in context. As databases of genetic information grow, genetic variants are associated with phenotypes, or observable traits. This can be compared to cross-referencing different books to get a better context for an unfamiliar word.
While a major part of the genome remains a mystery, what genomic sequencing does reveal must be protected. When genetic information can disclose both present and potential illnesses, any accidental release of this data has a high possibility of negatively impacting patients and their families. If a disease is detected before symptoms show, the patient may or may not want to know that they have a predisposition for an untreatable and ultimately fatal disease. This is an individual decision, and there is no right answer.
If a patient’s genetic information is released to the public, the patient may experience stigma. Employment and health insurance discrimination due to someone’s genetic information is illegal due to the Genetic Information Nondiscrimination Act of 2008, but that doesn’t prevent other types of societal discrimination, let alone the noncompliance of unscrupulous employers. Not only does genetic information suggest the traits of an individual, it also suggests the likely traits of their family members, who could then be discriminated against as well. To prevent the negative impacts of disclosing such sensitive information, the results of a patient’s genomic sequencing must be treated confidentially, and any analysis of results must take measures to protect the identity of the individual.
Before collecting such sensitive data through genomic sequencing, scientists and clinicians are responsible for obtaining a patient’s informed consent. And before giving informed consent, a patient has to know the scope of information that can be uncovered by genomic sequencing. Patients also need to know how the procedure can affect their quality of life. The potential positive outcomes from genomic sequencing—diagnosis, treatment, and knowledge—generally outweigh the slim chance of the data being used in an irresponsible way, but the patient must confront the possible negative outcomes. Once the patient has agreed to genomic sequencing, they may then decide whether or not they want to know any incidental findings for untreatable conditions, such as the presence of a marker for HD.
Renewing consent is one way to protect patients’ information as the meaning of findings from genomic sequences expands over time. Patients could then revisit their decision to keep the results of their genomic sequencing, which gives the patient control over their personal health information. Renewed consent also allows a child to give their own consent for genomic sequencing once they reach adulthood.
Our ability to understand DNA at such a detailed level has resulted and will continue to result in scientific breakthroughs that address the genetic components of health. At this point in time, genomic sequencing still raises more questions than answers, but these valuable questions give us an opportunity to shape the future of personalized medicine. Acknowledging the inherent ethical issues with analyzing such sensitive data allows genomic sequencing to do what it does best: shedding light on the molecule that gives instructions on building and sustaining every living thing.