J GM Journal of Genetic Medicine Sotos syndrome (SS, OMIM 117550) is characterized by prenatal and postnatal overgrowth with multiple congenital anomalies. However, there have been few cases of growth retardation caused by renal failure from infancy. We report a case of dysplasia of the bilateral kidneys with renal failure and poor postnatal growth. A 2-month-old boy visited the emergency room owing to poor oral intake and abdominal distension. He was born at the gestational age of 38 weeks with a birth weight of 4,180 g. After birth, he had feeding diffculty and abdominal distension. Upon physical examination, his height and weight were in less than the 3rd percentile, while his head circumference was in the 50th percentile on the growth curve. He also showed a broad and protruding forehead and high hairline. Blood laboratory tests showed severe azotemia; emergent hemodialysis was needed. Abdominal ultrasonography revealed bilateral renal dysplasia with multiple cysts and diffuse bladder wall thickening. A posterior urethral valve was suggested based on vesicoureterography and abdominal magnetic resonance findings. Results of a colon study to rule out congenital megacolon did not reveal any specific findings. The conventional karyotype of the patient was 46, XY. Array comparative genomic hybridization study revealed a chromosome 5q35 microdeletion including the NSD1 gene, based on which SS was diagnosed. We describe a case of SS presenting with end stage renal disease due to posterior urethral valve. The typical somatic overgrowth of SS in the postnatal period was not observed due to chronic renal failure that started in the neonatal period. Key words: NSD1, Overgrowth, Sotos syndrome, Posterior urethral valve, Chronic kidney failure. show additional clinical features including neonatal jaundice, congenital heart defects, brain anomalies, neonatal hypotonia, skeletal anomalies, and increased incidence of malignancy [2]. Among them, genitourinary defects such as vesico- ureteral reflux, multiple renal cysts, unilateral renal aplasia, and hypoplasia have been associated with about 15% of SS patients, with vesico-ureteral reflux being the most commonly observed [2]. A case of Sotos syndrome presented with end-stage renal disease due to the posterior urethral valve Won Im Cho 1 , Jung Min Ko 1,2, *, Hee Gyung Kang 1,2,3 , Il-Soo Ha 1 , and Hae Il Cheong 1,2,3 1 Department of Pediatrics, Seoul National University Children’s Hospital, Seoul, Korea 2 Research Coordination Center for Rare Diseases, Seoul National University Hospital, Seoul, Korea 3 Kidney Research Institute, Medical Research Center, Seoul National University College of Medicine, Seoul, Korea Case Report J Genet Med 2014;11(2):74-78 http://dx.doi.org/10.5734/JGM.2014.11.2.74 ISSN 1226-1769 (Print) 2383-8442 (Online) Introduction Sotos syndrome (SS, OMIM 117550) is an autosomal dominantly inherited congenital malformation syndrome characterized by four cardinal features: pre- and postnatal overgrowth, typical facial dysmorphism, macrocephaly, and variable degrees of mental retardation [1]. SS patients sometimes Received: 12 November 2014, Revised: 28 November 2014, Accepted: 4 December 2014, Published: 31 December 2014 *Corresponding author: Jung Min Ko, M.D., Ph.D. Department of Pediatrics, Seoul National University Children’s Hospital, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul 110-769, Korea. Tel: +82-2-2072-3570, Fax: +82-2-743-3455, E-mail: jmko@snu.ac.kr Conflict of interest: We declare that we do not have any conflicts of interests. ㏄ This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. c Copyright 2014 by the Korean Society of Medical Genetics www.e-kjgm.org