1. Department of Pediatrics, Division of Pediatric Endocrinology (D.N.L., S.M., E.L.G.-L.), The Johns Hopkins University School of Medicine, Baltimore, Maryland 21287
2. the Section of Pediatric Endocrinology (M.A.L.), The Cleveland Clinic Foundation, Cleveland, Ohio 44195
3. the Signal Transduction Section, Metabolic Diseases Branch (L.S.W.), National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892