Congenital nephrogenic diabetes insipidus (NDI) is a rare inherited disorder characterized by the excretion of large volumes of diluted urine resulting from resistance of the renal collecting duct to the antidiuretic hormone arginine vasopressin (AVP), and the clinical characteristics include polyuria, polydipsia, fever, hypernatremic dehydration, and constipation. The gene discussed is AVP; the disease is Polydipsia.