I’ve written about the Human Microbiome Project before, but, in a nutshell, it involves sequencing the microorganisms on us and in us. Basically, we take a biological sample–any collectable sample, preferably one that smells bad, and is icky and gross–will do, and sequence DNA from the sample. While some of the DNA will be microbial, much of it will be human (otherwise, DNA-based forensics wouldn’t work).
So why would this be a problem? In the Human Microbiome Project, the raw data are going to be deposited in a public access database*, including the human sequence data. The concern is that there could be enough human sequence to identify the person involved, particularly if there are other potentially identifying data (e.g., age, gender, location, and medical condition). To put this in perspective, the amount of human DNA sequenced would be roughly 250,000 times that used for forensic mitochondrial typing (obviously, this will depend on a variety of factors). Not only might the human subject be identified with this amount, but pre-existing medical conditions could be revealed. Imagine if your employer discovered that you would eventually contract Huntington’s Chorea, schizophrenia, or breast cancer and decided not to hire you.
With GINA, at least this problem is removed.
*Even if these data weren’t to be publicly available, they will still be acquired, and, consequently, breaches of genetic privacy could occur.