Fax +41 61 306 12 34 E-Mail karger@karger.ch www.karger.com Original Paper Nephron Physiol 2009;112:p53–p62 DOI: 10.1159/000225944 Mutational Analysis of CLC-5, Cofilin and CLC-4 in Patients with Dent’s Disease Fiona Wu a Anita A.C. Reed a Sian E. Williams a Nellie Y. Loh a Jonathan D. Lippiat b, c Paul T. Christie a Oliver Large a Alberto Bettinelli f Michael J. Dillon d Noemia P. Goldraich g Bernd Hoppe h Karl Lhotta i Chantal Loirat k Rayaz Malik e Delphine Morel l Peter Kotanko j Bernard Roussel m Dvora Rubinger n Connie Schrander-Stumpel o Erkin Serdaroglu p M. Andrew Nesbit a Frances Ashcroft b Rajesh V. Thakker a a Nuffield Department of Clinical Medicine, Academic Endocrine Unit, University of Oxford, and Churchill Hospital, Oxford Centre for Diabetes, Endocrinology and Metabolism, and b Department of Physiology, University of Oxford, Oxford, c Institute of Membrane and Systems Biology, Faculty of Biological Sciences, University of Leeds, Leeds, d Department of Nephrology, Great Ormond St Hospital for Children, London, and e Academic Department of Medicine, Manchester Royal Infirmary, Manchester, UK; f Unité Operative Pediatria, Ospidale Mandic, Merate, Italy; g Pediatric Nephrology Unit, Hospital de Clinicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; h Division of Pediatric Nephrology, Department of Pediatrics, University Hospital Cologne, Cologne, Germany; i Academic Teaching Hospital Feldkirch, Feldkirch, and j Department of Clinical Medicine, Krankenhaus der Barmherzigen Brüder, Graz, Austria; k Department of Pediatric Nephrology, Hospital Robert Debre, Paris, l Department of Nephrology, Groupe Hospitalier Pellegrin, Bordeaux, and m Nephrologie Pediatrique, American Memorial Hospital, Centre Hospitalier Universitaire Reims, Reims, France; n Nephrology Department, Hadassah-Hebrew University Medical Centre, Ein-Kerem Campus, Jerusalem, Israel; o Department of Clinical Genetics, University Hospital Maastricht and Research Institute for Growth and Development, University of Maastricht, Maastricht, The Netherlands; p Department of Pediatric Nephrology, Ege University Medical School, Izmir, Turkey mutation, one deletion-insertion (nt930delTCinsA) and an in-frame deletion (523delVal) were identified in 8 patients. In the remaining 10 patients, DNA sequence abnormalities were not detected in the coding regions of CLC-4 or cofilin, and were independently excluded for OCRL1. Patients with CLC-5 mutations were phenotypically similar to those without. The donor splice site CLC-5 mutation resulted in exon 3 skipping. Electrophysiology demonstrated that the 523delVal CLC-5 mutation abolished CLC-5-mediated chlo- ride conductance. Sixty percent of women with the CLC-5 deletion-insertion had nephrolithiasis, although calcium ex- cretion before and after oral calcium challenge was simi- lar to that in unaffected females. Conclusions: Three novel CLC-5 mutations were identified, and mutations in OCRL1, CLC-4 and cofilin excluded in causing Dent’s disease in this patient cohort. Copyright © 2009 S. Karger AG, Basel Key Words CLC-4  CLC-5  Cofilin  Dent’s disease  Mutations  OCRL1 Abstract Background/Aims: Dent’s disease is caused by mutations in the chloride/proton antiporter, CLC-5, or oculo-cerebro-re- nal-syndrome-of-Lowe (OCRL1) genes. Methods: Eighteen probands with Dent’s disease were investigated for muta- tions in CLC-5 and two of its interacting proteins, CLC-4 and cofilin. Wild-type and mutant CLC-5s were assessed in kid- ney cells. Urinary calcium excretion following an oral calci- um challenge was studied in one family. Results: Seven dif- ferent CLC-5 mutations consisting of two nonsense muta- tions (Arg347Stop and Arg718Stop), two missense mutations (Ser244Leu and Arg516Trp), one intron 3 donor splice site Received: October 24, 2008 Accepted: March 29, 2009 Published online: June 20, 2009 Prof. R.V. Thakker Academic Endocrine Unit, Nuffield Department of Clinical Medicine University of Oxford, OCDEM, Churchill Hospital Oxford, OX3 7LJ (UK) Tel. +44 1865 857 501, Fax +44 1865 857 502, E-Mail rajesh.thakker@ndm.ox.ac.uk © 2009 S. Karger AG, Basel 1660–2137/09/1124–0053$26.00/0 Accessible online at: www.karger.com/nep Downloaded by: University of Oxford 163.1.198.142 - 4/24/2014 11:14:02 AM