CASE REPORT A rare case report of simultaneous presentation of myopathy, Addison's disease, primary hypoparathyroidism, and Fanconi syndrome in a child diagnosed with Kearns–Sayre syndrome Meropi Tzoufi & Alexandros Makis & Nikolaos Chaliasos & Iliada Nakou & Ekaterini Siomou & Agathoklis Tsatsoulis & Anastasia Zikou & Maria Argyropoulou & Jean Paul Bonnefont & Antigone Siamopoulou Received: 25 March 2012 / Revised: 5 July 2012 / Accepted: 9 July 2012 / Published online: 9 August 2012 # Springer-Verlag 2012 Abstract Kearns–Sayre syndrome (KSS) is a rare mito- chondrial DNA deletion syndrome defined as the presence of ophthalmoplegia, pigmentary retinopathy, onset less than age 20 years, and one of the following: cardiac conduction defects, cerebellar syndrome, or cerebrospinal fluid protein above 100 mg/dl. KSS may affect many organ systems causing endocrinopathies, encephalomyopathy, sensorineu- ral hearing loss, and renal tubulopathy. Clinical presentation at diagnosis is quite heterogeneous and, usually, few organs are affected with progression to generalized disease early in adulthood. We present the case of a boy with KSS presenting at the age of 5 years with myopathy, Addison's disease, primary hypoparathyroidism, and Fanconi syn- drome. The proper replacement treatment along with the administration of mitochondrial metabolism-improving agents had a brief ameliorating effect, but gradual severe multisystemic deterioration was inevitable over the next 5 years. Conclusion This report highlights the fact that in case of simultaneous presentation of polyendocrinopathies and renal disease early in childhood, KSS should be considered. Keywords Kearns–Sayre syndrome . Fanconi syndrome . Addison's disease . Primary hypoparathyroidism Introduction Mitochondrial disorders that affect respiratory chain function are expected to have the greatest effect on organs with high energy requirements (e.g., brain, skeletal and cardiac muscle, sensory organs, and kidneys). Mutations in mitochondrial DNA (mtDNA) are associated with many of these disorders and usually are classified as point mutations, duplications, and deletions. The three main syndromes associated to mtDNA deletions are Pearson syndrome (OMIM#557000), chronic progressive external ophthalmoplegia (OMIM#157640), and Kearns–Sayre syndrome (KSS, OMIM #530000). In KSS, most of the mtDNA deletions are sporadic and are believed to occur probably at the germ cell level or very early in embryonic development [10]. KSS is characterized by the emergence before the age of 20 years, progressive external ophthalmoplegia, and pig- mentary retinopathy, with other heterogeneous features, Tzoufi Meropi and Makis Alexandros have equally contributed to this work. M. Tzoufi : A. Makis (*) : N. Chaliasos : I. Nakou : E. Siomou : A. Siamopoulou Child Health Department, Medical School, University of Ioannina, P.O. Box 1187, 45110, Ioannina, Greece e-mail: amakis@cc.uoi.gr A. Tsatsoulis Department of Endocrinology, Medical School, University of Ioannina, Ioannina, Greece A. Zikou : M. Argyropoulou Department of Radiology, Medical School, University of Ioannina, Ioannina, Greece J. P. Bonnefont INSERM U781, Université Paris Descartes, Paris, France J. P. Bonnefont Service de Génétique Médicale, Hospitalier Necker Enfants Malades, Assistance Publique, Paris, France Eur J Pediatr (2013) 172:557–561 DOI 10.1007/s00431-012-1798-1