The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, UK. rd3@sanger.ac.uk <rd3@sanger.ac.uk>|The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, UK. rd3@sanger.ac.uk <rd3@sanger.ac.uk>|The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, UK. rd3@sanger.ac.uk <rd3@sanger.ac.uk>