Uncorrected Proof Iran J Pediatr. In Press(In Press):e100056. Published online 2020 October 4. doi: 10.5812/ijp.100056. Research Article Could Drainage Related Ultrasonography Prevent Unnecessary Interventions in Patients with Wolfram Syndrome? Mehrzad Mehdizadeh 1 , Sahar Eftekharzadeh 2 , Sediqe Hosseini Shabanan 2 , Maryam Sobhani 3 and Abdol-Mohammad Kajbafzadeh 2, * 1 Department of Radiology, Children’s Medical Center, Tehran University of Medical Sciences, Tehran, Iran 2 Pediatric Urology and Regenerative Medicine Research Center, Children’s Medical Center, Tehran University of Medical Sciences, Tehran, Iran 3 Iranian Blood Transfusion Research Center, High Institute for Research and Education in Transfusion Medicine, Tehran, Iran * Corresponding author: Pediatric Urology and Regenerative Medicine Research Center, Children’s Medical Center, Tehran University of Medical Sciences, Tehran, Iran. Email: kajbafzd@sina.tums.ac.ir Received 2019 December 10; Revised 2020 August 01; Accepted 2020 August 11. Abstract Background: Upper urinary tract dilation, the most common urological manifestation of the Wolfram syndrome (WS), is mainly non-obstructive and secondary to other components of the disease such as diabetes insipidus. Misdiagnosis of the type of the hy- droureter in Wolfram patients and encountering them as obstructive uropathies has led to ineffectual surgeries such as ureter re- implantation. Based on previous studies drainage related ultrasonography (DRUS) is a beneficial means of distinction between obstructive and non-obstructive hydroureters. Objectives: To avoid unnecessary interventions in patients with WS by detecting hydroureters’ types using DRUS. Methods: Seven patients (14 ureters) with a mean ± SD age of 24.43 ± 4.25 months who were diagnosed with WS were included in this retrospective study. The definite diagnosis of the non-obstructive type of hydroureter was assessed by appropriate imaging modalities. The maximum diameter of these 14 ureters, before (D1) and after (D2) 3 hours of catheterization were observed by ultra- sonography. Values were recorded as D ratio ( [(|D1 - D2|)/D1] × 100) and the cutoff point of 22% for D ratio was set to discriminate the subtypes of the hydroureter. Results: Measurement of maximum diameter of ureter prior to catheterization indicated a mean ± SD diameter of 20.64 ± 2.73 mm; decreasing to 11.07 ± 2.64 mm after 3 hours of catheterization which indicates a significant decrease. Mean D ratio of 14 hy- droureters was 45.95 ± 13.01% which indicated significantly higher percentage than 22%, revealing that hydroureters’ type in WS is non-obstructive. Conclusions: DRUS is a useful method for the assessment of the hydroureter’s type in WS and it could prevent performing unnec- essary surgeries in WS patients. Keywords: Ultrasonography, Wolfram Syndrome, Urinary Tract Disease, Hydronephrosis 1. Background Wolfram syndrome (WS) is a rare hereditary neurode- generative disease that was first described by Wolfram and Wagener in 1938 (1). This syndrome is characterized by coin- cidence of early-onset diabetes mellitus and optic atrophy, followed by a wide spectrum of manifestations affecting different organs, including sensorineural deafness, uro- logical abnormalities, psychological abnormalities, and endocrine disorders (2). WS prevalence is estimated to be around 1 in 68,000 - 770,000, differing based on racial differences (3, 4). This syndrome bears a poor prognosis and yet there is no ef- fective treatment to prevent its progression. The mortality rate in patients under 35 years old is 65% and patients af- fected by WS have a median life expectancy of 30 years (5). The first causative genetic mutation was found in WFS1 locus which encodes Wolframin, an endoplasmic reticu- lum (ER) transmembrane protein involved in membrane trafficking and regulation of ER calcium homeostasis. Wol- fram syndrome type 2 is due to mutations in the CISD2 gene that encodes another ER intramembranous protein. Both types of WS are usually inherited in an autosomal re- cessive pattern (6, 7). Although urinary tract dysfunctions include upper tract dilatation and bladder dysfunctions are amongst common reported manifestations of WS, their etiology is still unclear but the main hypotheses behind these dys- Copyright © 2020, Author(s). This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International License (http://creativecommons.org/licenses/by-nc/4.0/) which permits copy and redistribute the material just in noncommercial usages, provided the original work is properly cited.