We believe the evidence presented by Weir is insufficient to reject the hypothesis that the infants described in our report had inappropriate secretion of antidiuretic hormone (SIADH). First, we reported the fluid intake for each of the patients in our series and noted that the volume ingested did not exceed the limits of renal excretory function. The maximum tolerable water intake is estimated to be 750 See Table in the PDF File ml/kg/day at 2 weeks of age and declines to 550 ml/kg/ day at 1 year of age.1