Congenital adrenal hyperplasia associated with hyperphosphatemic rickets.

The authors describe a boy with precocious puberty due to adrenal hyperplasia associated with rickets, hypocalcemia, hyperphosphatemia, elevated PTH and alkaline phosphatase levels, and concentrations of 25-OH-D and 1,25-(OH)2D at the upper limit or above normal range. Treatment with hydrocortisone for 9 months did not normalize hypocalcemia and hyperphosphatemia. The addition of 1,25-(OH)2D3 (0.5-2 micrograms/day) to the corticoid treatment for 1 year was followed by a progressive normalization of plasma calcium, phosphorus, PTH and alkaline phosphatase concentrations with improvement of the osteomalacia on bone biopsy.