The Privacy Implications of Human DNA Sequencing



Deoxyribonucleic acid, or DNA, has been known as the hereditary material in living cells since 1944. It was discovered, in part, by Halifax-born Oswald Avery. Since being discovered, scientists have made significant progress in figuring out how DNA is manufactured, copied, and used by living cells. Most importantly, in the last decade we have become remarkably good at “sequencing” the genetic code: decoding the DNA molecules so that we can read the genetic blueprint, much like one would translate a book from one language to another.

Being able to sequence DNA has provided many opportunities for researchers and clinicians alike to understand the nature and likelihood of some hereditary diseases. It has also allowed us to identify persons who are genetically-related to one another. Databases, both public and private, are being built to collect and store this genetic data. Examples include private companies like 23andMe and AncestryDNA, along with public databases like GEDMatch.

A variety of privacy and intimate-information issues stem from obtaining and storing personal DNA sequence information. For example, AncestryDNA provides a genetic heritage analysis, allowing an individual to learn where their DNA tells them they are from. (It should be noted that the ability of these tests to identify heritage correctly has been called into question). This information can be shared with others, dependent on the privacy selections an individual makes on their profile. It is essential that customers ensure their privacy settings are as they want them to be, to ensure their data stays private (if that’s what they wish).

“Playing with Code Fire” by Ade McOran-Campbell (2011). Image description: Painting of person sitting cross-legged in a field, with the sun overhead. Person is playing with a double helix.

In addition, companies that collect genetic information to determine health risks – if you are a cystic fibrosis carrier for example – can learn things about themselves that they may otherwise wish not to know, or would want to keep out of the hands of others (e.g. insurance companies). Most strikingly, you not only learn your own health risks, but inadvertently you learn about your parents’ and relatives’ genetic codes as well. Your genetic code is hereditary after-all, meaning you receive your genes (and their associated health-risks) from your parents.

Recently, a suspect in a string of sexual assaults and murders in the United States was identified by police through a DNA sequence match on GEDMatch works by allowing individuals to upload their personal genetic information to the database, in the hopes of identifying genealogical information. Police, undoubtedly through a genetic genealogist, used DNA samples collected at the crime scene to link the suspect to a family member who had uploaded their information to GEDMatch. This provided the police with the information they needed to make an arrest. This example highlights an additional use of publicly available genetic information that many people were unaware of. This particular example is worrying. Although the end in this case – catching and subduing a suspected serial killer and rapist – was undeniably good, the family member who uploaded their DNA sequence to GEDMatch was likely unaware of how it would be used. This ultimately puts the family member in the position of “genetic informant” without their knowledge. As such, this particular case has raised many questions about how police should be able to use genealogy websites and their associated data. Further issues are raised by the fact that the use of DNA sequences in this way is not always accurate. DNA evidence was used to link a San Francisco film-maker to a murder that police later found out he did not commit.

Canadian law currently prevents the use of genetic information to discriminate for housing, employment and insurance, with significant criminal consequences if that law is violated. Canadians, however, are only covered by this law while in Canada. This does not prevent genetic information from being used for a variety of other things by private companies in other countries. David Fraser, a Halifax privacy lawyer, issued a warning in a 2018 CBC interview that “this is some of the most sensitive information that exists,” and that not everyone considers the implications of DNA testing. In writing this, I wished to echo that statement: DNA testing provides a wealth of information that can be used in a variety of ways, both good and bad.

However, it is important that consumers are aware of what they are getting into and what the private companies will do with their information once the DNA sequencing is complete. Ultimately, understanding these details allows consumers to make informed decisions about this extremely personal information.


Landon J. Getz is a M.Sc. Candidate with the Department of Microbiology and Immunology at Dalhousie University. @landongetz