Presented in part at the Endocrine Society's 88th Annual Meeting, 24 June 2006.
Utility of AVP gene testing in familial neurohypophyseal diabetes insipidus
Article first published online: 20 MAY 2008
© 2008 The Authors. Journal compilation © 2008 Blackwell Publishing Ltd
Volume 69, Issue 6, pages 926–930, December 2008
How to Cite
Chitturi, S., Harris, M., Thomsett, M. J., Bowling, F., McGown, I., Cowley, D., Leong, G. M., Batch, J. and Cotterill, A. M. (2008), Utility of AVP gene testing in familial neurohypophyseal diabetes insipidus. Clinical Endocrinology, 69: 926–930. doi: 10.1111/j.1365-2265.2008.03303.x
- Issue published online: 12 NOV 2008
- Article first published online: 20 MAY 2008
- (Received 3 October 2007; returned for revision 23 October 2007; finally revised 29 February 2008; accepted 15 May 2008)
Context Familial neurohypophyseal diabetes insipidus (FNDI) is a rare disorder resulting from arginine vasopressin (AVP) gene mutations. A partial defect in AVP secretion occurs early in the course of FNDI and may not be detected by a water deprivation test (WDT). Testing for AVP gene mutations may confirm a diagnosis of FNDI when a WDT is inconclusive and may also predict individuals who will later develop FNDI.
Objective To test the utility of AVP gene analysis in confirming the diagnosis of FNDI.
Patients Five families (20 subjects, 14 symptomatic and six asymptomatic) with FNDI and nine children with idiopathic neurohypophyseal diabetes insipidus (INDI).
Measurements Genomic DNA was analysed for AVP gene mutations using polymerase chain reaction (PCR) amplification and sequencing.
Results Heterozygous AVP gene mutations were found in all subjects with FNDI but none of the ICDI patients. Each family had their own distinct mutation. We identified two novel mutations (C44W and C105S). One asymptomatic subject developed diabetes insipidus (DI) 4 months after detection of an AVP gene mutation. The WDT suggested partial DI in 4/6 but was normal in 2/6 children with FNDI.
Conclusion AVP gene testing allowed diagnostic confirmation of FNDI when the WDT was inconclusive in symptomatic children, therefore obviating the need for a repeat WDT and enabling earlier initiation of appropriate treatment. AVP gene testing also has the potential to identify which asymptomatic children will later develop FNDI.