We also observed how patients with RSW display significantly higher mean urodilatin levels than both patients with (median 5.46 vs. 0.57 ng/mL, p = 0.006) or without hyponatremia (median 5.46 vs. 0.27 ng/mL, p < 0.001) (Figure 1). The gene discussed is NPPA; the disease is Hyponatremia.