Isolated cortisol deficiency: a rare cause of neonatal cholestasis.

For decades, congenital panhypopituitarism has been recognized to cause infantile cholestasis. However, the identity of the hormone whose deficiency causes such derangement of the liver is not clear. Here, we report four cases of isolated severe cortisol deficiency presenting with neonatal cholestasis and hypoglycemia, of whom two had familial primary glucocorticoid deficiency and the other two had isolated adrenocorticotropin deficiency. The resolution of cholestasis by hydrocortisone replacement therapy suggests a causal relationship between cortisol deficiency and the development of neonatal cholestasis. In conclusion, the presentation of a young infant with cholestasis and hypoglycemia should alert pediatricians to the possibility of cortisol deficiency and prompt investigation of adrenal function should be undertaken.