1. Medical Research Council Harwell Institute, Harwell OX11 0RD, UK
2. MRC Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine (IGMM), University of Edinburgh, Edinburgh EH4 2XU, UK
3. BGI Hong Kong, 26/F, Kings Wing Plaza 2, 1 On Kwan Street, Shek Mun, New Territories, Hong Kong
4. School of Computer Science, University of Lincoln, Lincoln LN6 7TS
5. Mouse Imaging Centre, Hospital for Sick Children, Toronto, Ontario M5T 3H7, Canada