Today marks another entrant in the personal genomics game: Navigenics, the much anticipated startup out of Redwood Shores, Ca, is open for business.

The company arrives as direct competition to 23andMe and DeCodeMe, both of which began offering direct-to-consumer genotyping last year. Navigenics was originally planning to launch around the same time as the competition, but ended up taking several months longer to fine-tune it’s product. As planned, Navigenics is taking a more clinical approach to personal genomics, with a more overt pitch towards the medical implications.

I had the opportunity to visit the company last week and get a preview of the service. Here are a few standout observations.

1) The Results: Navigenics launches offering results on 18 diseases, from glaucoma to colon cancer to Alzheimer’s. This is about the same number as 23andMe had at it’s launch, though they’re now up to 58 different conditions.

One big distinction is that 23andMe lets users peruse the entire results of their genotype run – more than 500,000 different SNPs. Navigenics, even though they’re using a 1 million SNP chip (as does DecodeMe), is more circumspect with its results, only letting customers see the results for those conditions they’ve vetted.

2) The Business Model: As has been anticipated, Navigenics will charge an initial fee of $2,500 for a one year membership – and then an annual fee of $250. This compares with about $1000 for permanent access at 23andMe and DecodeMe.

That's been criticized as a bad deal, especially since you can't look at the 1 million results. But Navigenics offers an intriguing twist: It will freeze your spit sample, allowing the company to re-test your DNA as more associations with different SNPs are discovered (and deemed scientifically valid). Mari Baker, Navigenics' CEO, says they expect to go back two or three times a year to extract more data points.

That means that there's a clear trade off: with 23andMe, you're buying into today's technology, and they promise to show you everything they have. With Navigenics, they're not going to show you everything, but they promise to keep you up to date as the technology and the science improve.

3) The Calls: One thing you notice when you get your 23andMe results is how subtle the differences are between the average person’s risk for disease and your own. For colorectal cancer, for instance, my 23andMe results tell me that I have a .21 out of 100 chance of developing the disease, compared to a .26 out of 100 average risk. That may be scientifically valid distinction, but as a consumer it is so slight as to be no difference.

Navigenics uses a different method of calculating your genetic risk. I won’t get into the details here, but basically they make a “Lifetime Risk analysis” that results in what they believe are stronger calls. Certainly the numbers are more emphatic; examples I saw showed, for instance, a person with a 51 percent risk of heart disease, compared to an average 42 percent risk. That’s a striking difference.

4) The Physician: Navigenics puts a great deal of emphasis on the utility of genotype data for useful medical insights. It’s clearly one of their main selling points. To that end, “we’re putting education towards the top of our agenda,” says Mari Baker, and they’ve bankrolled an online continuing medical education course on Genomic and Personalized Medicine with Medscape. What’s more, they suggest customers bring doctors their Health Compass Report, a primer for personal physicians explaining what the company does, how it calculates risk, and what their patients results might precondition them for. To me, this is a bold and aggressive endorsement of the power of genomic data for real-time medical insights, much stronger than anything 23andMe has done. It’ll be interesting to see how the medical community responds.

So it’s a more high-fidelity environment, with less flexiblity for the user. And though 23andMe gets lots of attention because of their founders’ Google connection, make no mistake: Navigenics is as blue-chip as they come, with top management from T-Gen and Kleiner Perkins.

Long and short: Yesterday personal genomics was an oddity. Today, it’s an industry.

This is a cross-post from WIRED SCIENCE