Genetic Tests Limitations

With Trumps FDA authorization, millions of consumers have bought genetic test kists like 23andme. (Source)

https://www.technologyreview.com/s/610233/2017-was-the-year-consumer-dna-testing-blew-up/

Both for ethnic background and health conditions research

Until last year, genetic testing firms like 23andMe were prevented from selling health risk reports to the public.

The Food and Drug Administration imposed a moratorium on such tests in 2013 out of concerns that the results might be misleading.

Under the Trump administration, the FDA has allowed 23andMe to reintroduce the tests. The company now tests for variants related to nine diseases and carrier status for more than 40 conditions.

But there is still no guarantee that its results provide adequate or complete information about a customer’s profile or health risks.

From a blood test genetic counselors can determine health conditions like pathogenic mutation in my BRCA2 gene.

This means chance of a recurrence of breast cancer was substantially higher than for a woman without a BRCA mutation. It also meant my chance of having ovarian cancer and pancreatic cancer was higher.

Angela Joli   a double mastectomy rather than lumpectomies. I then had my ovaries and fallopian tubes removed, as recommended, plunging me into surgical menopause at the age of 41.

A genetic counselor takes a family history of three generations, explains treatment guidelines and, if the patient chooses, tests her for thousands of mutations in several genes related to breast cancer and other cancers. The sessions are in-depth. A first visit with a cancer genetics specialist might take as long as 90 minutes. If the patient’s results show an inherited mutation, a second visit is typically scheduled to discuss screening and management options as well as risk to other family members.

This kind of education and care is not provided in a 23andMe spit kit. Though there is a lot of fine print, there is no counseling to speak of. (The company does provide contact information for the National Society of Genetic Counselors in its report.)

Had I learned about my mutation via email, as 23andMe customers do, I would have had to find healthcare providers to help me navigate its meaning. I would have been terribly lost at an enormously vulnerable point in my life.

Not only does 23andMe not provide counseling, their results are incomplete. For instance, they report only on BRCA1 and BRCA2 and restrict their findings to the three mutations common among Jewish women. (They do explain this in their printed materials.)

While the most common three mutations in the BRCA1 and BRCA2 genes are typically found in women of Ashkenazi Jewish heritage, there are more than 1,000 other mutations that can be just as deadly. Women with Ashkenazi heritage can also have a mutation not associated with being Ashkenazi.

There are other genes that can have mutations that substantially increase one’s risk for breast cancer, including PALB2, CHEK2, PTEN, CDH1, TP53 and STK11. 23andMe doesn’t provide test results for any of these mutations.

It’s because 23andMe’s health data provide a limited picture that the FDA made the company stop. The agency was concerned, and reasonably so, that a negative result might lead a woman to think her risk was not high, when in fact she could still carry a different mutation than the three tested. Conversely, a woman might receive a positive test result and undergo a risk-reducing double mastectomy when a different option might have been more appropriate.

None of these risks have been addressed. Instead, the FDA simply allowed 23andMe to downgrade their kits from Class III devices, which receive the highest level of safety scrutiny, to Class II devices.

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