1. Department of Genetics, Biology, and Biochemistry (B.P., B.F.), University of Turin, Turin, Italy
2. Section on Endocrinology and Genetics and Pediatric Endocrinology Training Program (L.M., T.B., M.M., S.B., C.A.S.), Developmental Endocrinology Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892
3. Department of Laboratory Medicine and Pathology (J.A.C.), Mayo Clinic, Rochester, Minnesota 55905