By Kevin Davies
December 8, 2009 | For the past few weeks, Emily Enns has been helping a small but motivated group of consumers navigate their way through the potentially complex world of personal genomics. Enns is one of the certified genetic counselors on staff at Pathway Genomics, a San Diego-based consumer genomics firm that recently joined the ranks of the “big three” – 23andMe, Navigenics, and deCODEme – offering whole-genome genotypic information.
Pathway’s emergence comes on the second anniversary of the launch of deCODEme and 23andMe. According to CSO David Becker, Pathway views itself as somewhere between 23andMe’s social networking model and Navigenics’ medical establishment approach.
In some areas, such as carrier status for Mendelian disorders and drug response, Pathway offers as much if not more information than the other platforms. It also offers information on paternal and maternal ancestry. And as mentioned, it has an in-house genetic counseling program, similar to Navigenics. But it does not offer ancestry painting, relative finder or other web 2.0 features that are a hallmark of 23andMe.
Results Are In
Earlier this year, I submitted a saliva sample to Pathway to get a feel for how the latest consumer genomics offering compares to the more established companies in the field. Pathway communicates the health results not by a numerical relative or lifetime risk but via a series of color-coded bins depending on their potential significance to the individual. Green denotes below average risk; beige = average. Yellow and Orange signify above average risk. Red denotes “Immediate Attention,” and is primarily reserved for Mendelian disorders.
I was happy to see I had nothing in either the red or orange tiers. Among the health conditions tested for are Alzheimer’s disease, macular degeneration, diabetes, and coronary artery disease, among 25 conditions.
The calculated risk scores favored by other consumer genomics firms have come in for criticism because of the inter-platform variability reported by numerous commentators, including Craig Venter and colleagues, due to differences in the number of SNPs, the algorithms used, and other factors. Pathway performs its own risk calculations, but argues that in light of the preliminary and/or imprecise nature of the calculations, it is misleading to communicate those values. As if to accentuate the imprecise nature of just focusing on genetic factors, Pathway also presents a qualitative estimate of individual risk based on self-reported lifestyle factors alongside the genetic results.
Pathway spokesperson Maurissa Bornstein told Bio-IT World: “Pathway has not included an aggregate percentage risk because there are other factors that may contribute to the development of disease, such as environment and lifestyle, and we feel that presenting a specific number implies a degree of precision that is simply not there.” Instead, Pathway has elected to communicate genetic, lifestyle, and population information in parallel, delivering to the consumer a broad set of data which, it hopes, the individual will discuss with their doctor if so desired. (A PDF summary report of the client’s results should be available soon.)
An undoubted strength of the Pathway platform are the depth of information on carrier status and drug response. For carrier status, Pathway tests for 36 disorders, including many disorders covered in the Ashkenazi Jewish panel (including Tay-Sachs, Bloom syndrome, Canavan’s disease, and familial dysautonomia). I learned that I was a carrier for hemochromatosis, which I already knew, and galactosemia, which I did not.
Among the recessive conditions Pathway screens for is cystic fibrosis. The test is more comprehensive than any of the DTC platforms, covering 79 mutations in the CFTR gene. By contrast, 23andMe only tests for the most common delF508 mutation.
There are currently nine drug response indicators, including clopidogrel. I am a fast metabolizer of caffeine, but learned that I would likely not have an adverse reaction to statins and typical sensitivity to the anti-coagulant warfarin. Although as a male, I’m highly unlikely to develop breast cancer, I carry one non-functional CYP2D6, which would likely decrease my response to Tamoxifen. Curiously, Pathway currently communicates prostate cancer but not breast cancer results for men. Enns said there were ongoing discussions about changing that policy.
For now, there is no easy mechanism to obtain the raw SNP/genotype results, as the other DTC companies provide (either via download or CD). But it is coming. “This is your information and you are certainly entitled to it,” said Bornstein. Becker says the information will be made available as soon as Pathway is satisfied that the novel SNPs on its custom chip are validated.
Pathway’s combined health and ancestry test is just $348, the least expensive option available. (23andMe is $499, deCODEme $985, Navigenics $999). The path to success in the consumer genomics business just got a little more crowded and a lot more interesting.