One short newswire article, three spikes in my blood pressure. Impressive!
Just before heading off on a short vacation last week I spotted the news item about the two new genetic association studies which report on restless leg syndrome.
The lead paragraph drove the first spike: "suggesting the twitching condition...is biologically based". Now, I've elided the pop cultural reference for clarity, not because it was the problem (I'm actually a huge Seinfeld fan). I was left wondering what other causes were ascribed to a condition which is treatable by medication which has passed at least one double-blind placebo-controlled trial? Poltergeists? Ah, perhaps they're suggesting it is purely psychosomatic?
While away I saw in another paper a longer version of the same item -- with still no explanation of what else, besides physiology, might result in restless legs.m
But going further, spike number two. The article mentions that Kari Stefansson was an author. I don't have an inherent bias against company-sponsored or company-driven research, but why wasn't the fact he is the head of DeCode mentioned? That's important background information -- DeCode has succeeded again, but also has inherent financial conflicts of interest.
The final two paragraphs gave the kicker: a doctor pooh-poohing the results by email, complaining that it is "overhyped" and "doesn't pin down what the condition is, who has it, or what medication is needed". Gimme complete solutions or shut up, in other words. Now, I am somewhat surprised that DeCode got their paper in New England Journal of Medicine, given the small number of genetics papers published there it is striking that a relatively routine linkage study for a non-fatal disorder was published there, but editors get to pick what they like.
Via a post on Freakonomics I finally discovered some of the background missing from the newspaper items. The same doctor (Steven Woloshin) quoted in the newspaper item had recently published in PLoS Medicine an article claiming that restless legs syndrome is a poster child for "disease mongering" by pharmaceutical companies and their dupes/comrades in the media.
If one steps back from the dust & smoke, the papers are intriguing (well, the abstracts -- I don't normally have access to either journal though NEJM is apparently, at least at the moment, making the full text freely available) first because they each found the same gene (though the second paper found two more). BTBD9 is not a well-characterized gene, but it contains a BTB domain, a protein domain involved in protein-protein interactions. So, one clear path forward is to identify the interaction partners of BTBD9.
Each abstract has some additional, apparently unique information, which is intriguing. DeCode reports that the BTBD9 variant is also linked to reduced serum ferritin levels and that ferritin levels have been previously implicated in restless legs syndrome. They also report higher levels of other movements during sleep in individuals carrying the variant. The Nature Genetics paper reports linkages to one gene and an intergenic region, with the one gene (MEIS1)
previously implicated in limb development.
Hints & suggestions: no, it doesn't tell Dr. Woloshin how to treat or prescribe, but it does suggest a route towards understand the pathology, which will probably not include poltergeists.