Pseudohypoparathyroidism Type II: Restoration of Normal Renal Responsiveness to Parathyroid Hormone by Calcium Administration

Abstract

A patient with the clinical features of pseudohypoparathyroidism and skeletal resistance to parathyroid hormone is described. The renal defect was similar to that previously reported in Pseudohypoparathyroidism Type II, e.g., increase in the urinary excretion of cyclic AMP in response to parathyroid hormone administration but no rise in the urinary excretion of phosphate. Further studies demonstrated that the renal response could be restoredto normal by the administration of calcium with or without elevated levels of endogenous immunoreactive parathyroid hormone. The renal defect in pseudohypoparathyroidism Type II may be related to abnormal permeability of the tubular cells to calcium in response to parathyroid hormone or cyclic AMP.