title: Clinical overview of nephrogenic diabetes insipidus based on a nationwide survey in Japan.
abstract: BACKGROUND
  Nephrogenic diabetes insipidus (NDI) is a rare disease whose complications include polyuria, renal dysfunction, growth disorder and mental retardation. The details of NDI's clinical course have been unclear. To address this uncertainty, we performed a large investigation of the clinical course of NDI in Japan.
  
  
  METHODS
  Between December 2009 and March 2011, we provided a primary questionnaire to 26,282 members of the Japan Endocrine Society, the Japanese Urological Association, the Japanese Society for Pediatric Endocrinology, the Japanese Society for Pediatric Nephrology, the Japanese Society of Nephrology, the Japanese Society of Neurology and the Japanese Society of Pediatric Urology. In addition, we provided a secondary questionnaire to 121 members who reported experience with cases of NDI. We asked about patient's age at onset, diagnosis, complications, effect of treatment and patient's genotype.
  
  
  RESULTS
  We enrolled 173 patients with NDI in our study. Of these NDI patients, 143 were congenital and 30 were acquired. Of the 173, 73 patients (42%) experienced urologic complications. Among the 143 with congenital NDI, 20 patients (14%) had mental retardation. Patients with NDI mainly received thiazide diuretics, and some patients responded to treatment with desmopressin acetate (DDAVP). Gene analyses were performed in 87 patients (61%) with congenital NDI, revealing that 65 patients had an arginine vasopressin receptor type 2 (AVPR2) gene mutation and that 8 patients (9.2%) had an aquaporin 2 (AQP2) gene mutation. Patients with the AVPR2 mutation (D85N) generally showed a mild phenotype, and we found that DDAVP was generally an effective treatment for NDI among these patients.
  
  
  CONCLUSIONS
  We suggest that adequate diagnosis and treatment are the most important factors for improving prognoses. We further suggest that gene analysis should be performed for optimal treatment selection and the early detection of NDI among siblings.
authors.affiliation: Division of Pediatrics & Perinatology, Tottori University Faculty of Medicine, Yonago 683-8504, Japan.
authors.forename: Masanobu
authors.initials: M
authors.lastname: Fujimoto
authors.affiliation: Division of Pediatrics & Perinatology, Tottori University Faculty of Medicine, Yonago 683-8504, Japan.
authors.forename: Shin-Ichi
authors.initials: S
authors.lastname: Okada
authors.affiliation: Division of Pediatrics & Perinatology, Tottori University Faculty of Medicine, Yonago 683-8504, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Kawashima
authors.affiliation: Division of Pediatrics & Perinatology, Tottori University Faculty of Medicine, Yonago 683-8504, Japan.
authors.forename: Rei
authors.initials: R
authors.lastname: Nishimura
authors.affiliation: Division of Pediatrics & Perinatology, Tottori University Faculty of Medicine, Yonago 683-8504, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Miyahara
authors.affiliation: Division of Pediatrics & Perinatology, Tottori University Faculty of Medicine, Yonago 683-8504, Japan.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Kawaba
authors.affiliation: †Department of Women's and Children's Family Nursing, Tottori University Faculty of Medicine, Yonago 683-8504, Japan.
authors.forename: Keiichi
authors.initials: K
authors.lastname: Hanaki
authors.affiliation: ‡Division of Functional Genomics, Research Center for Bioscience and Technology, Tottori University, Yonago 683-8504, Japan.
authors.forename: Eiji
authors.initials: E
authors.lastname: Nanba
authors.affiliation: §Health Care Services Management, Nihon University School of Medicine, Tokyo 173-0032, Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Kondo
authors.affiliation: ‖Department of Pediatrics, Graduate School of Medicine, University of Tokyo, Tokyo 113-8655, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Igarashi
authors.affiliation: Division of Pediatrics & Perinatology, Tottori University Faculty of Medicine, Yonago 683-8504, Japan.
authors.forename: Susumu
authors.initials: S
authors.lastname: Kanzaki
keywords: aquaporin 2; deamino arginine vasopressin; nephrogenic diabetes insipidus; thiazide diuretics; vasopressin v2 receptor