23andme: taking genetic tests to the next level

The biotech world has been quite eventful these days.  In February 2015, there was the announcement of FDA’s approval of 23andme’s DTC test for Bloom’s Syndrome, which has generated renewed interest in the power of personal genetic testing.  Direct-to-consumer personal genetic testing has been around for years, but its value has mostly been limited to the information repository it provides on the consumer’s ancestral characteristics as well as some physical traits.  What can I benefit from knowledge of the colour of my eyes or my hair?  Not much, but these tests certainly have great entertainment value, and to their credit, genetic labs have done a remarkable advertising campaign.   But for makers of these tests, they have also wanted to take their business to the next level – to provide health-related genetic tests complete with health reports.  However, without the blessing of government regulatory authorities, they might as well put their dream on hold.  This is why the news that 23andme has been given the greenlight to sell Bloom’s test kits without premarket clearance is well received in the media.

A simplified regulatory pathway for a health-related genetic test is a welcome move.  However Bloom’s syndrome is a well characterized autosomal recessive disease caused by mutations in one genetic locus.    The Bloom’s carrier test is a rather straightforward, and the simplicity of the genetic origin of this disease contributed to its FDA approval. Like the simplicity of Bloom’s, there are a large number of diseases caused by defects in a single gene such as cystic fibrosis, sickle-cell anemia or Huntington’s disease to name a few. It is not a stretch to say that Bloom’s approval has opened the door to DTC genetic testing for these single-locus diseases.   But there is also a vast world of diseases such as cancer and autism that cannot be traced to a single gene, but a cluster of mutations throughout the genome.  There is also no clear consensus within the scientific community.  However, it is these multiple-origin diseases that are the most financially lucrative since they are more prevalent.  Without clear science, regulatory hurdles for a personal genetic test in the latter category will likely prevent private labs from going any further, at least not in the near future.  To recap, a clearance for Bloom’s test is welcome news for a commercial lab, but we should not interpret this approval as indicator of a wide embrace of DTC genetic testing for diseases.  Also, while a shift in FDA’s thinking opens the door to carrier tests, the most these tests would help you identify is the 25% chance that you and a carrier spouse could produce a child with two defective copies of a genetic locus.  In other words, Bloom’s test and other related tests do not provide you with much more information than say where your ancestors came from.  We are still a long way from the day DTC tests will help us make important health decisions backed by FDA approval.










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