Renal-nonresponsive, bone-responsive pseudohypoparathyroidism. A case with normal vitamin D metabolite levels and clinical features of rickets.

Clinical signs of rickets developed in a previously healthy 13-year-old girl with normal features. She had hypocalcemia, hyperphosphatemia, elevated alkaline phosphatase and parathyroid hormone levels, and normal vitamin D metabolite levels, with osteitis fibrosa cystica on bone biopsy specimen. Her renal function was normal. Treatment with 1 microgram of calcitriol each day resulted in symptomatic and clinical relief and improvement of the serum chemical values. This patient probably has pseudohypoparathyroidism type 1, with renal nonresponsiveness and bone responsiveness. This disorder has the clinical features of rickets, but represents hyperparathyroid bone disease.