1. Department of Medical Genetics, University of Wisconsin, Madison, Wisconsin 53706
2. Department of Pathology, University of Wisconsin, Madison, Wisconsin 53706
3. Department of Oral Biochemistry, School of Dentistry at Niigata, The Nippon Dental University, 1-8 Hamaura-Cho, Niigata 951, Japan
4. Department of Medical Genetics, University of Wisconsin, Madison, Wisconsin 53706, Department of Medicine, University of Wisconsin, Madison, Wisconsin 53706