Genetic testing has progressed a great deal since it was first made available to the mass market. More than being used for identifying birth rights and ancestries, genetic testing has spawned a larger, more functional market of detecting disease.

By screening for high-risk or defective genes within an individual’s genetic data, pivotal information could be obtained about probable cancers and hereditary diseases. This information is then able to guide individuals to take necessary precautionary measures – and, if needed, pre-emptive medical care. These days, genetic testing companies are able to provide test kits to healthcare providers, offering a simple and cost effective way of carrying out genetic testing. Unfortunately, the accuracy of these genetic testing has come under fire when one company’s compromised test has resulted in close to a year’s worth of possibly inaccurate data.

Errors in cancer screening tests

The incident in question, revolves around the genetic testing company, Invitae, whose genetic test missed out upon a rare mutation, Boland inversion – linked to an increased risk of developing colon cancer. Boland inversion errors are found in patients with Lynch syndrome. While it does not guarantee the development of colon cancer, it greatly increases the risk of developing the malignancy.

The error was first noticed when a patient with Lynch syndrome received a negative test result despite prior laboratory tests having proven otherwise. Invitae was then notified of the error by a genetic counsellor which prompted the company to take immediate actions towards its genetic test. The cause of the error was linked to a recent update of the test testing procedure which resulted in an omission of the components necessary to detect Boland inversion.

Thus far, the error has gone unchecked for 11 months with 50,000 blood and saliva samples needing to be rechecked. Invitae is currently working on reanalysing all the results with two false negatives having been detected so far. Of all the 50,000 samples that needs to be retested, the company expects there to be less than 10 patients who were affected by the error.

The company spokesperson accounted for the company’s error, stating, “Our quality control checks were insufficient to identify the error based on the infrequency of the occurrence of this variant,” while reassuring that necessary steps have been taken. “We’ve designed three new quality checks to ensure this type of error does not happen again.”

Nevertheless, the damage had been done not to Invitae solely; but on the reputation of genetic testing as a whole. Experts have often lamented the lack of central regulation and oversight for genetic testing with many of the tests carried out by private institutions. Moreover, genetic testing is often poorly understood by the public with most expecting the results to be perfect. In light of these event, experts have begun to bring up the need for more oversight of the validity of genetic testing results.

Risks and limitations of genetic testing

More than just the chance of detection errors, genetic testing carries its own fair share of risks and limitations just like every other medical test before it. Although a great deal of genetic testing is computer-aided, it still carries a small physical risk especially with prenatal testing. Acquiring a sample of amniotic fluid or tissue surrounding the foetus for prenatal testing carries a small risk of miscarriage, and is something pregnant women need to be made aware of.

Anxiety and stress over test results is just one of the few risks faced by individuals who carry out genetic testing.
Anxiety and stress over test results is just one of the few risks faced by individuals who carry out genetic testing.

Besides that, the age old adage, “ignorance is bliss”, holds true for genetic testing too as the results may be associated with emotional, social or financial consequences. It is not uncommon for individuals to feel angry, depressed, uncertain, anxious or guilty about the results of their genetic testing. Moreover, the social consequences of genetic tests may sometimes put a strain on familial relationship and marriages.

Results of genetic testing may end up becoming a financial burden for individuals, who choose to take pre-emptive medical action, which is not covered by medical insurance. On the other hand, insurance premiums and coverage costs may also increase if genetic tests reveal a high risk of debilitating or pre-existing conditions. This phenomenon is known as genetic discrimination and extends towards employers of insurance companies who take exclusionary actions towards the individual. While citizens of the United States are protected by the Genetic Information Non-discrimination Act (GINA), the problem still persists especially in countries without such protective laws.

Despite its rising adoption rates, genetic testing is still only able to provide limited information about inherited conditions and often does not detail the severity of one’s condition. As such, one major limitation lies in the lack of treatment strategies for those diagnosed with genetic disorders. For genetic conditions with established treatment, the decision to go ahead with medical treatment is often ambiguous due to the lack of information into the natural history of the disease. Meanwhile, a large majority of other genetic disease lack definitive treatment which nullifies the benefit of early detection while bringing about unwanted future anxiety. Ultimately, the decision falls into the hands of the individual but often, the information provided is not near sufficient to help make those decisions.

The bottom line

While genetic testing has allowed for the early detection of genetic disorders with relative ease and low cost, it is not without its fair share of risks and limitations. Invitae’s error in detecting Lynch syndrome patients is just one of the few ways that genetic testing may lull users into a false sense of security with false negatives. That on top of other pitfalls to genetic testing, it serves to emphasize the need for regulation and better public awareness into genetic testing. MIMS

Read more:
Iceland’s story of eradicating Down Syndrome
Revisiting the Human Genome Project and other health studies for a more holistic view of genetic diseases
FDA approves sale of genetic tests for disease risk

Sources:
http://gizmodo.com/a-genetic-testing-company-just-screwed-up-50-000-cancer-1810016063
https://ghr.nlm.nih.gov/primer/testing/riskslimitations
https://www.acmg.net/docs/LDT_Release.pdf
http://www.eurogentest.org/index.php?id=622
https://ghr.nlm.nih.gov/primer/testing/discrimination