Familial glucocorticoid deficiency in a girl with familial hypophosphatemic rickets.

Familial glucocorticoid deficiency is a rare multisystem disorder characterized by glucocorticoid deficiency with normal mineralocorticoid activity, achalasia of the cardia, and alacrima. Familial hypophosphatemic rickets is characterized by selective renal phosphate wasting with subsequent hypophosphatemia and an inappropriately low 1,25-dihydroxyvitamin D concentration for the degree of hypophosphatemia. A 6-year-old girl with both disorders is described. A biochemical relationship between familial glucocorticoid deficiency and familial hypophosphatemic rickets could not be defined; the influence of cortisol on her serum calcium level, phosphorus level, and rickets, as well as the natural history of these two entities, is described.