1. MRC Human Genetics Unit, Western General Hospital, Crewe Rd, Edinburgh, EH4 2XU, UK
2. Department of Cell and Developmental Biology, Biocenter of the University of Würzburg, 97074 Würzburg, Germany
3. Center for Genomics and Bioinformatics (CGB) and Department of Cell and Molecular Biology (CMB), Karolinska Institutet, Berzelius väg 35, S-171 77 Stockholm, Sweden