Notably, in 3 out of 4 patients with urinary output > 5 L daily who underwent inpatient WDT starting at 6 a.m. the test was stopped early, resulting in a water deprivation of less than 8 h: 4 h in one AVP-D case due to hypernatremia and 7 h in two PP patients due to hypotension and UOsm raise respectively (copeptin values at the end of the WDT were 1.3 and 2.1 pmol/l). This evidence concerns the gene AVP and Hypernatremia.