1. Department of Pediatrics, University of Iowa, Iowa City, IA 52245, USA.
2. Department of Biology , University of Iowa, Iowa City, IA 52245, USA.
3. Fox Chase Cancer Center, Philadelphia, PA 19111-2412, USA.
4. Marshfield Medical Research Foundation, Marshfield, WI 54449, USA.
5. Department of Genetics, Harvard Medical School, Boston, MA 02115-5716, USA.
6. Généthon, Evry 91000, France.
7. Centre Hospitalier de l'Université Laval, Quebec, Canada G1 K 7P4.
8. INSERM, Paris 75010, France.
9. Eccles Institute for Human Genetics, University of Utah, Salt Lake City, UT 84112, USA.
10. Department of Genetics, Yale University, New Haven, CT 06510, USA.
11. CEPH, Paris 75010, France.