Pseudohypoparathyroidism presenting as renal osteodystrophy

Abstract

Pseudohypoparathyroidism (pseudo HPT) is the prototype of a group of diseases with end organ unresponsiveness to parathyroid hormone (PTH). Patients with the classic form of this disease have both renal and osseous resistance to PTH. We describe a rare variant of pseudo HPT with classic renal unresponsiveness to PTH but normal skeletal responsiveness to this hormone. The latter patients develop metabolic bone disease in response to depressed calcium and elevated PTH levels. Skeletal abnormalities are histologically and radiologically indistinguishable from renal osteodystrophy and these patients frequently present in childhood with symptoms relating to slipped capital femoral epiphyses. The latter radiologic findings, in the face of normal renal function or the classic somatic features of the syndrome, are highly suggestive of pseudo HPT with normal skeletal responsiveness to PTH.

Pseudohypoparathyroidism as a rare cause of bilateral slipped capital femoral epiphysis

“…In addition to surgical fixation, medical treatment with active vitamin D analogs is therefore required to suppress the PTH and to prevent subsequent treatment failure. In our patient, the distal femoral physeal changes were seen due to the effects of increased PTH, which has been documented in previously reported cases of PHP 411–13. Treatment with calcitriol (1,25-dihydroxyvitamin D 3 ) is generally recommended to normalize the elevated PTH because calcitriol does not require PTH for its activation 4…”

“…We conducted a literature search in Medline using the terms “slipped capital femoral epiphysis” and “pseudohypoparathyroidism” and found only three case reports 41113. Review of the citations in these articles revealed another pertinent article,12 increasing the total number of PHP patients with SCFE to five (including the patient reported here).…”

Severe hypercalcemic hyperparathyroidism developing in a patient with hyperaldosteronism and renal resistance to parathyroid hormone

“…These biopsy findings plus osteosclerosis have been previously reported in PHP‐1 patients 7, 28–31. The target organ manifestations seen in PHP‐1b include renal resistance to PTH and varying degrees of bone sensitivity to PTH, ranging from skeletal resistance to the hormone to normal sensitivity manifested by osteitis fibrosa cystica or low bone mineral density on dual‐energy X‐ray absorptiometry 32–35. Cultured osteoblast‐like cells from a patient with PHP type 1b demonstrated normal cAMP responsiveness to PTH despite the lack of a renal response 7…”

Pseudohypoparathyroidism: A rare cause of bilateral slipped capital femoral epiphysis

“…All patients previously reported with the exception of one 5 were much older and showed good clinical response to medical management alone. 5,6,7 The growth plate of the proximal femoral epiphysis is composed of interlocking metaphyseal bony hills and corresponding epiphyseal valleys that together restrain displacement of malleable growth cartilage. Renal osteodystrophy, a combination of rickets and secondary hyperparathyroidism, is a frequent metabolic cause of SCFE.…”