Hypoparathyroidism and pseudohypoparathyroidism.

Hypoparathyroidism is a clinical disorder characterized by hypocalcemia and hyperphosphatemia in the absence of renal failure and hypomagnesemia. The causes of hypoparathyroidism can be classified as two groups: (i) insufficient parathyroid hormone (PTH) secretion in relation to the serum calcium level (hypoparathyroidism); and (ii) impaired PTH action (pseudohypoparathyroidism). The main emphasis in this report is to distinguish subgroups based on the etiology and pathophysiology of the various aspects of the disease.