Nat. Genet. 42, 786–789 (2010); published online 15 August 2010; corrected after print 27 October 2010

In the version of this article initially published, the name of author Peter Vollenweider was incorrectly written as Peter Vollenwider. Also, Claudio Bassetti's affiliation was incorrectly listed as Neurocentro (Ente ospedaliero cantonale) della Svizzera Italiana, Ospedale Civico, Lugano, Switzerland. His correct affiliation is Department of Neurology, University Hospital Zurich, Zurich, Switzerland. These errors have been corrected in the HTML and PDF versions of the article.