1. Aix Marseille University, Marseille Medical Genetics, INSERM U1251 and Assistance Publique Hopitaux de Marseille, La Conception Hospital, Department of Endocrinology, Marseille 13005, France
2. Diabetes, Endocrinology and Obesity Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
3. Medizinische Klinik und Poliklinik IV, Klinikum der Universität, Ludwig-Maximilians-Universität München, Munich 80336, Germany
4. Department of Oncology and Metabolism, University of Sheffield, Sheffield, S10 2TN, UK