1. L. A. Pennacchio, Department of Genetics, Stanford University School of Medicine, and Department of Biology, Stanford University, Stanford, CA 94305, USA.
2. A.-E. Lehesjoki, K. Virtaneva, J. Miao, E. D'Amato, A. de la Chapelle, Department of Medical Genetics, University of Helsinki, Haartmaninkatu 3, 00290 Helsinki, Finland.
3. N. E. Stone, V. L. Willour, L. Ramirez, M. Faham, J. A. Warrington, D. R. Cox, R. M. Myers, Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305, USA.
4. M. Koskiniemi, Department of Virology, University of Helsinki, Haartmaninkatu 3, 00290 Helsinki, Finland.
5. R. Norio, Department of Medical Genetics, Finnish Population and Family Welfare Federation, 00100 Helsinki, Finland.