Diagnostic criteria based on accurately quantifiable factors (e.g., plasma urea, atrial natriuretic peptide, antidiuretic hormone and other serum markers) have not been demonstrated to be accurate predictors of hyponatremia etiology in all cases, and their use in the evaluation of hyponatremia is not supported by the literature (Class III evidence) [24]. The gene discussed is NPPA; the disease is Hyponatremia.