Nat. Genet. 47 803–808 (2015); published online 25 May 2015; corrected after print 8 July 2015

In the version of this article initially published, there was an error with the affiliations for author Roman Chrast. His correct affiliations are: Department of Medical Genetics, University of Lausanne, Lausanne, Switzerland; Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden; and Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden. The error has been corrected in the HTML and PDF versions of the article.