Zelal Bircan1, Hatice Mutlu, Hae Il Cheong. 1. Department of Pediatric Nephrology, Kocaeli University School of Medicine, Kocaeli, Turkey. zbircan@superonline.com
Abstract
PURPOSE: The causes of hereditary nephrogenic diabetes insipidus (HNDI) are the mutations in the arginine vasopressin V2 receptor gene (AVPR2) (90%) and aquaporin 2 gene (AQP2) (10%). Although it is possible to perform mutation analysis where available, differentional diagnosis at clinical bases remains valuable. METHODS: In this report we present two cases of HNDI diagnosed at clinical bases with a desmopressin infusion test as AQP2 gene mutations. The results were verified by genetic analysis to stress that a desmopressin infusion test is valuable for differential diagnosis of HNDI. RESULTS: With a desmopressin infusion test, factor VIII levels were increased up to 219% and 214% respectively, establishing the presence of V2 receptor. With direct sequencing of the AQP2 gene, a previously described splicing mutation in a new codon (380) and a new frameshift mutation were determined in case 1 and case 2 respectively. CONCLUSION: It is concluded that the desmopressin infusion test is a simple and reliable method for the diagnosis and differential diagnosis of HNDI in early childhood.
PURPOSE: The causes of hereditary nephrogenic diabetes insipidus (HNDI) are the mutations in the arginine vasopressin V2 receptor gene (AVPR2) (90%) and aquaporin 2 gene (AQP2) (10%). Although it is possible to perform mutation analysis where available, differentional diagnosis at clinical bases remains valuable. METHODS: In this report we present two cases of HNDI diagnosed at clinical bases with a desmopressin infusion test as AQP2 gene mutations. The results were verified by genetic analysis to stress that a desmopressin infusion test is valuable for differential diagnosis of HNDI. RESULTS: With a desmopressin infusion test, factor VIII levels were increased up to 219% and 214% respectively, establishing the presence of V2 receptor. With direct sequencing of the AQP2 gene, a previously described splicing mutation in a new codon (380) and a new frameshift mutation were determined in case 1 and case 2 respectively. CONCLUSION: It is concluded that the desmopressin infusion test is a simple and reliable method for the diagnosis and differential diagnosis of HNDI in early childhood.
Authors: R Vargas-Poussou; L Forestier; M D Dautzenberg; P Niaudet; M Déchaux; C Antignac Journal: J Am Soc Nephrol Date: 1997-12 Impact factor: 10.121