Hyponatremia resulting from Arginine Vasopressin Receptor 2 gene mutation

Abstract

Chronic hyponatremia, unless associated with extracellular fluid volume expansion, is an infrequent electrolyte imbalance in pediatrics. We report an infant with chronic hyponatremia suggestive of a syndrome of inappropriate secretion of antidiuretic hormone (SIADH), in the absence of ADH secretion. A mutation was found in the same codon of the gene that results in a loss-offunction of arginine vasopressin receptor 2 (AVPR2) observed in congenital nephrogenic diabetes insipidus. In this case, a gain-of- function of AVPR 2 was found to be responsible for a SIADH-like state.Chronic hyponatremia, unless associated with extracellular fluid volume expansion, is an infrequent electrolyte imbalance in pediatrics. We report an infant with chronic hyponatremia suggestive of a syndrome of inappropriate secretion of antidiuretic hormone (SIADH), in the absence of ADH secretion. A mutation was found in the same codon of the gene that results in a loss-offunction of arginine vasopressin receptor 2 (AVPR2) observed in congenital nephrogenic diabetes insipidus. In this case, a gain-of- function of AVPR 2 was found to be responsible for a SIADH-like state. Keywords Seizure . Syndrome of inappropriate secretion of antidiuretic hormone . AVPR2 .Water excretion . Nephrogenic syndrome of inappropriate antidiuresis . Hypo-osmolarity syndrome of inappropriate antidiuresisSeizure . Syndrome of inappropriate secretion of antidiuretic hormone . AVPR2 .Water excretion . Nephrogenic syndrome of inappropriate antidiuresis . Hypo-osmolarity syndrome of inappropriate antidiuresis.