Keywords
case report
water reabsorption
arginine vasopressin receptor 2 gene mutation
novel variant
Categories
How to Cite
Abstract
Congenital nephrogenic diabetes insipidus (NDI) is a rare hereditary renal disorder caused by variants in the arginine vasopressin receptor 2 (AVPR2) or aquaporin 2 (AQP2) genes, resulting in the kidney’s inability to concentrate urine.
We report the case of a 52-day-old boy presenting with feeding difficulties and poor weight gain. Laboratory findings revealed hypernatremia and hyperchloremia, associated with a marked disparity between high serum osmolality and low urine osmolality. Genetic analysis identified a novel missense variant in the AVPR2 gene. The therapeutic approach consisted of nasogastric free water supplementation and oral hydrochlorothiazide therapy, with good clinical response.
This case highlights the importance of early recognition and genetic testing in infants with suspected diabetes insipidus and expands the phenotypic spectrum of AVPR2-related NDI.