ABSTRACT
Nephrogenic syndrome of inappropriate antidiuresis (NSIAD) is a rare X-linked genetic condition caused by a gain-of-function mutation of arginine vasopressin receptor 2 gene, AVPR2. We report the case of a male neonate diagnosed with NSIAD based on his DNA sequence of the AVPR2 gene and the clinical course. He demonstrated a complete correction of hyponatremia using oral urea. We suggest that (1) sequencing analysis of the AVPR2 gene ought to be done in newborns with prolonged euvolemic hyponatremia, hypo-osmolality, high urinary sodium and normal/low or undetectable AVP levels, and that (2) oral urea is a safe and effective treatment option in infants diagnosed with NSIAD until the patients are grown-up.
ABSTRACT
PURPOSE: Ureteral duplication is a relatively common congenital urinary tract abnormality that can be associated with various clinical problems such as vesicoureteral reflux (VUR), hydronephrosis, and ectopic ureters. The purpose of this study was to analyze the clinical characteristics of pediatric patients with recently diagnosed ureteral duplication and to identify any differences from those described in previous reports.METHODS: We retrospectively reviewed the clinical characteristics and course of pediatric patients who were diagnosed with ureteral duplication between January 2008 and June 2017.RESULTS: A total of 32 pediatric patients were diagnosed with ureteral duplication during the study period. The male to female ratio was 1:2.2. Twenty-seven patients (84.4%) were first diagnosed with ureteral duplication at less than 3 months of age, and 26 (81.3%) were first diagnosed by prenatal ultrasonography. Four of the 32 patients were diagnosed with bilateral ureteral duplication, for a total of 36 occurrences of ureteral duplication. In 17 occurrences of complete ureteral duplication (47.2%), other urinary tract anomalies were also found; namely, ureterocele (7), VUR (11), and ectopic ureter (5). However, none of the patients with incomplete ureteral duplication had ureterocele or VUR.CONCLUSION: With the advent of routine prenatal ultrasound, ureteral duplication is being diagnosed earlier than was previously possible, enabling timely treatment of the various accompanying urinary tract anomalies. Multicenter studies are needed to establish guidelines for standardized evaluation and treatment of ureteral duplication.