Clinical ResearchHeterogeneous Genetic Alterations in Sporadic Nephrotic Syndrome Associate with Resistance to ImmunosuppressionGiglio, Sabrina*,†; Provenzano, Aldesia*; Mazzinghi, Benedetta†; Becherucci, Francesca‡; Giunti, Laura†; Sansavini, Giulia‡; Ravaglia, Fiammetta‡; Roperto, Rosa Maria‡; Farsetti, Silvia‡; Benetti, Elisa§; Rotondi, Mario‖; Murer, Luisa§; Lazzeri, Elena¶; Lasagni, Laura¶; Materassi, Marco‡; Romagnani, Paola*,‡,¶ Author Information *Department of Biomedical Experimental and Clinical Sciences “Mario Serio,” and ¶Excellence Centre for Research, Transfer and High Education for the Development of DE NOVO Therapies (DENOTHE), University of Florence, Florence, Italy; †Medical Genetics and ‡Pediatric Nephrology Units, Meyer Children’s University Hospital, Florence, Italy; §Department of Pediatrics, University of Padua, Padua, Italy; and ‖Unit of Internal Medicine and Endocrinology, Fondazione Salvatore Maugeri IRCCS, University of Pavia, Pavia, Italy Correspondence: Dr. Sabrina Giglio or Prof. Paola Romagnani, Department of Biomedical Sciences, University of Florence, Viale Pieraccini 6, 50139 Florence, Italy. Email: [email protected] or [email protected] Received November 4, 2013 Accepted May 4, 2014 Journal of the American Society of Nephrology 26(1):p 230-236, January 2015. | DOI: 10.1681/ASN.2013111155 Buy Metrics Abstract In children, sporadic nephrotic syndrome can be related to a genetic cause, but to what extent genetic alterations associate with resistance to immunosuppression is unknown. In this study, we designed a custom array for next-generation sequencing analysis of 19 target genes, reported as possible causes of nephrotic syndrome, in a cohort of 31 children affected by sporadic steroid-resistant nephrotic syndrome and 38 patients who exhibited a similar but steroid-sensitive clinical phenotype. Patients who exhibited extrarenal symptoms, had a familial history of the disease or consanguinity, or had a congenital onset were excluded. We identified a genetic cause in 32.3% of the children with steroid-resistant disease but zero of 38 children with steroid-sensitive disease. Genetic alterations also associated with lack of response to immunosuppressive agents in children with steroid-resistant disease (0% of patients with alterations versus 57.9% of patients without alterations responded to immunosuppressive agents), whereas clinical features, age at onset, and pathologic findings were similar in steroid‐resistant patients with and without alterations. These results suggest that heterogeneous genetic alterations in children with sporadic forms of nephrotic syndrome associate with resistance to steroids as well as immunosuppressive treatments. In these patients, a comprehensive screening using such an array may, thus, be useful for genetic counseling and may help clinical decision making in a fast and cost-efficient manner. Copyright © 2015 The Authors. Published by Wolters Kluwer Health, Inc. All rights reserved.