Correction to: European Journal of Human Genetics (2013) advance online publication, 9 January 2013; doi:10.1038/ejhg.2012.269
Since the publication of this article, the authors asked for the additional affiliation of two authors, Isabelle Pénisson-Besnier and Norma Romero. These have now been added and the amended article appears in this issue. The HTML and online PDF versions have also been amended and now carry the additional affiliations.
The online version of the original article can be found at 10.1038/ejhg.2012.269