Candidate-gene studies have validated associations between multiple sclerosis and polymorphic variants within the major histocompatibility complex (MHC), but no other loci with a definitive association with the disease have been found.
The study in Nature found similar findings. Before I say shame on the media for hyping this association I would like to put these numbers called odds ratios into context.
An odds ratio of 1 indicates that the condition or event under study is equally likely in both groups. An odds ratio greater than 1 indicates that the condition or event is more likely in the first group. And an odds ratio less than 1 indicates that the condition or event is less likely in the first group. In this case the odds ratio of having MS would be more likely if you carried the studied polymorphisms mentioned above. But not by much!!!
Let me give you an example. In patients who carry a single change in one of their clotting factors, Factor V Leiden the relative risk of developing a blood clot is 7. Yet when combined with other rsik factors like smoking and obesity, only a whopping 10% ever develop blood clots!
Granted relative risk is slightly different than Odds Ratios. It does tend to measure on the more conservative side... since relative risk is a more intuitive measure of effectiveness, the distinction is important especially in cases of medium to high probabilities. If action A carries a risk of 99.9% and action B a risk of 99.0% then the relative risk is just over 1, while the odds associated with action A are almost 10 times higher than the odds with B.
In medical research, the odds ratio is favored for case-control studies and retrospective studies. Relative risk is used in randomized controlled trials and cohort studies. For more explanation click here
I hope you are still following me. What this means is that an Odds Ratio less than 2 is not impressive. In fact it gives misleading data.
The Sherpa Says: Even with the most tightly linked data discovered over 30 years ago, we still have no curative therapies for Multiple Sclerosis. What that means to me is that we have no clue as to the true molecular mechanisms of this heterogeneous disease. Stay away from the DTC tests that will likely spring up from these studies. Never take a test for risk without the Odds Ratio being at least 2. Now shame on you media, for just publishing press releases and not doing the due diligence regarding these findings!