Genetics Expert Nancy Cohen Weighs in on the Benefits Genetic Testing

The certified genetic counselor at Northern Westchester Hospital lays out the pros and cons of genetic testing kits.



In a world where we’re growing more and more concerned with our personal data, there is perhaps no data more personal than our own DNA. That may be why our genetics became the focus of a Silicon Valley company, 23andMe, which was co-founded by Anne Wojcicki (who was married to, and is now separated from, Google co-founder Sergey Brin).

For $99, 23andMe allowed its clients to send in a DNA sample that it would test in its labs. The company would then return a report laying out all the genetic data, from mutations and dispositions to certain diseases to information about ancestry—even how much “Neanderthal” DNA existed in a sample. The goal is to identify what health risks might be hidden in your genes, so that you can follow up with your doctor and see if treatment might be necessary. 

That is, that was the goal until the FDA stepped in. It ordered 23andMe to stop marketing its materials, saying that the FDA “did not have any assurance that the firm has analytically or clinically validated the [Personal Genome Service, or PGS] for its intended uses.” 

So, is personal genomic testing a good way to get people to start thinking about their genetic health? Or is the FDA right, and is the risk of acting on false positives—say, prophylactic surgery for someone who was identified to be a carrier for breast cancer—doing more harm than good?

We asked Nancy Cohen, MS, CGC, a certified genetic counselor at Northern Westchester Hospital. “I believe genetic testing offers people the opportunity to identify health risks and take appropriate action to decrease or manage those risks,” she says. “While the 23andMe tests do provide some information regarding possible health risks, a person’s genetic makeup needs to be evaluated in the context of an individual’s personal and family health history. 23andMe provides results directly to consumers without the benefit of education and counseling by a genetic counselor or other trained health professional provide.” Changes to health management based on the results of this test, she says, “might be inappropriate or even harmful. More useful information may, in fact, be gained from a thorough personal and family history than from some of the genetic information provided in these tests.” Unless, of course, all you want is to see how much Neanderthal DNA you have.