Case Report
Copyright ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Cases. Dec 26, 2020; 8(24): 6418-6424
Published online Dec 26, 2020. doi: 10.12998/wjcc.v8.i24.6418
Congenital nephrogenic diabetes insipidus due to the mutation in AVPR2 (c.541C>T) in a neonate: A case report
Fa-Tao Lin, Jing Li, Bang-Li Xu, Xiu-Xiu Yang, Fang Wang
Fa-Tao Lin, Jing Li, Bang-Li Xu, Xiu-Xiu Yang, Department of Neonatology, Children’s Hospital Affiliated to Zhengzhou University, Henan Children’s Hospital, Zhengzhou Children’s Hospital, Zhengzhou 450000, Henan Province, China
Fang Wang, Department of Infectious Diseases, Children’s Hospital Affiliated to Zhengzhou University, Henan Children’s Hospital, Zhengzhou Children’s Hospital, Zhengzhou 450000, Henan Province, China
Author contributions: Lin FT, Li J and Xu BL contributed to the conception and design of this study; Lin FT and Xu BL drafted the manuscript; Lin FT, Li J, Xu BL, Yang XX and Wang F critically reviewed the manuscript and supervised the entire study process; All authors performed the data acquisition and statistical analysis, and read and approved the final manuscript.
Informed consent statement: Informed consent was obtained for this case report.
Conflict-of-interest statement: The authors declare that they have no competing interests.
CARE Checklist (2016) statement: The authors have read the CARE Checklist (2016), and the manuscript was prepared and revised according to the CARE Checklist (2016).
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Bang-Li Xu, MD, Doctor, Professor, Department of Neonatology, Children’s Hospital Affiliated to Zhengzhou University, Henan Children’s Hospital, Zhengzhou Children’s Hospital, No. 33 Longhu Outer Ring East Road, Zhengzhou 450000, Henan Province, China. 371107983@qq.com
Received: July 27, 2020
Peer-review started: July 27, 2020
First decision: September 29, 2020
Revised: October 6, 2020
Accepted: October 27, 2020
Article in press: October 27, 2020
Published online: December 26, 2020
Abstract
BACKGROUND

Congenital nephrogenic diabetes insipidus (CNDI) is a rare hereditary renal disorder that is caused by mutations in AVPR2 or aquaporin 2 (AQP2). Up to now, there are few reports about CNDI in neonates. Early clinical manifestations of CNDI in neonates are atypical. A lack of understanding of the disease by clinicians causes frequent misdiagnoses or missed diagnoses, which may result in failure to administer treatments in time and ultimately leads to severe complications. In this study, clinical data of a case of AVPR2 gene mutation-induced CNDI, which was confirmed by genetic testing, were retrospectively analyzed to improve our understanding of this disease.

CASE SUMMARY

On February 1, 2020, a male neonate was hospitalized 17 d after birth due to a 7 d period of pyrexia. The patient’s symptoms included recurrent pyrexia, hypernatremia and hyperchloremia, which were difficult to treat. The patient was fed on demand, and water was additionally provided between milk intakes. A combination treatment of hydrochlorothiazide and amiloride was administered. After the treatment, body temperature and electrolyte levels returned to normal, the volume of urine was significantly reduced and the patient was subsequently discharged. Genetic tests confirmed that the patient carried the AVPR2 gene missense mutation c.541C>T (P.R181C), and the patient’s mother carried a heterozygous mutation at the same locus. After clinical treatment with a combination of hydrochlorothiazide and amiloride, the body temperature and electrolyte levels returned to normal. Up until the most recent follow-up examination, normal body temperature, electrolyte levels and growth and development were observed.

CONCLUSION

CNDI in the neonatal period is rare, and its clinical manifestations are unspecific with some patients merely showing recurrent fever and electrolyte disturbance. Genetic testing of AVPR2 and AQP2 can be used for screening and genetic diagnosis of CNDI.

Keywords: Neonate, Congenital nephrogenic diabetes insipidus, AVPR2 gene, Gene mutation, Magnetic resonance imaging, Case report

Core Tip: Congenital nephrogenic diabetes insipidus (CNDI) is a rare hereditary renal disorder. There are few reports about CNDI in neonates. Early clinical manifestations of CNDI in neonates are atypical. In cases of neonates exhibiting pyrexia of unknown cause accompanied by hypernatremia, which is difficult to correct, diabetes insipidus should be considered. Urine volume and urine specific gravity should be monitored closely, and genetic screening should be conducted as soon as possible to facilitate a definitive diagnosis.