1. Centre for Medical Genetics, Department of Cytogenetics and Molecular Genetics, Women's and Children's Hospital, North Adelaide, South Australia 5006, Australia.
2. Center for Human Genome Studies and Life Sciences Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA.
3. Centre d'Etude du Polymorphisme Humain, F-7501 01, Paris, France.