1. Endocrinology and Diabetes Research Group (E.F.-R., I.G., L.C., G.P.d.N.), Hospital de Cruces, Barakaldo, Basque Country, 48903 Spain
2. Endocrine Unit (M.B., E.F.-R.), Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114
3. Pediatric Endocrinology (B.G.-C.), Hospital Leganés, 28911 Madrid, Spain
4. Centro de Investigación Biomédica en Red en Enfermedades Raras (I.G., L.C., G.P.d.N.), Barakaldo, 48903 Bizkaia, Spain
5. Genetadi Biotech (C.L.), Parque Tecnologico de Bizkaia, 48160 Derio, Spain
6. Unidad de Genetica y Diagnostico Prenatal (F.M.), Hospital Universitario La Fe, 46009 Valencia, Spain
7. Biochemistry (C.G.-L.), Hospital Leganés, 28911 Madrid, Spain
8. University of the Basque Country School of Medicine (L.C.), 48940 Bilbao, Spain