Familial pseudohypoparathyroidism without somatic anomalies.

A family is described in which affected individuals showed pseudohypoparathyroidism, with hypocalcemia, hyperphosphatemia and increased serum levels of parathyroid hormone, but none of the somatic anomalies frequently associated with this disorder. The untreated individuals showed radiologic evidence of osteitis fibrosa. The administration of parathyroid hormone evoked only a slight increase in the excretion of cyclic adenosine monophosphate but no change in the renal tubular reabsorption of phosphate and no rise in the serum calcium level. The infusion of ethylenediamine tetra-acetic acid caused an appropriate increase in the serum level of parathyroid hormone, but again there was no apparent renal or skeletal response to the hormone. There were no associated abnormalities in calcitonin, thyrotropin or prolactin levels and no thyroid dysfunction. Therapy with vitamin D corrected the hypocalcemia but did not improve the renal and skeletal responsiveness to parathyroid hormone. The inheritance of the disorder in this family was compatible with an autosomal dominant mode with variable penetrance, but other modes could not be excluded.