Water homeostasis is of critical importance for virtually all processes in the human body. Maintaining a proper water balance is regulated by the antidiuretic hormone arginine-vasopressin that can bind to the vasopressin v2 receptor in the kidney, thereby stimulating water reabsorption from the pro-urine via aquaporin-2 (aqp2) water channels. Patients with inherited nephrogenic diabetes insipidus (ndi) are unable to concentrate their urine, despite the presence of avp, which is due to mutations in the gene encoding the v2r (X-linked) or aqp2 (autosomal recessive or dominant). This review describes the clinical phenotype of ndi, differences in its diagnosis, the cell biological mechanisms underlying ndi, and how these contribute to the development of new therapies.
