European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Genome Campus, CB10 1SD Hinxton, Cambridge, UK.|Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK.|CRUK Cambridge Institute, University of Cambridge, Cambridge CB2 0RE, UK.|Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK.