Copeptin levels exceeding the 97.5 percentile of normal healthy individuals (corresponding to a copeptin level of 11.25 pmol/L) were significantly (p = 0.0099, Chi square test for trend) more often observed in malaria patients presenting with moderate-to-severe hyponatraemia (25 of 31 [81%] patients) than in patients with patients with mild hyponatraemia (47 of 68 [69%] patients) and normonatraemia (60 of 105 [57%] patients). The gene discussed is AVP; the disease is Hyponatremia.