1. Division of Endocrinology, Diabetes, and Metabolism (S.D.M., L.B., M.E.G.), Childrens Hospital Los Angeles, University of Southern California Keck School of Medicine, Los Angeles, California 90027
2. Departments of Medicine, Physiology, and Human Genetics (G.N.H., L.C., I.M.), McGill University, and Calcium Research Laboratory and Hormones and Cancer Research Unit, Royal Victoria Hospital, Montreal, Quebec, Canada H3A 1A1
3. Department of Pediatrics (R.A.F.), Kaiser Permanente, Los Angeles, California 90027
4. Departments of Laboratory Medicine and Pathobiology, Medicine, and Pediatrics (Genetics) (D.E.C.C.), University of Toronto, Toronto, Ontario, Canada M5G 1L5
5. The Saban Research Institute of Childrens Hospital Los Angeles (M.E.G.), Los Angeles, California 90027