Hypoparathyroidism

© 2018 Elsevier Inc. All rights reserved. Hypoparathyroidism is characterized by hypocalcemia and hyperphosphatemia due to a lack of parathyroid hormone (PTH) secretion or action. Hypoparathyroidism may occur as part of a pluriglandular autoimmune disorder or as a complex congenital defect, as for example in the autosomal dominant DiGeorge or hypoparathyroidism, deafness, and renal dysplasia (HDR) syndromes. In addition, hypoparathyroidism may occur as a solitary endocrinopathy and this has been called isolated or idiopathic hypoparathyroidism. Familial occurrences of isolated hypoparathyroidism with autosomal dominant, autosomal recessive, and X-linked inheritances have been established. Studies of patients with these forms of hypoparathyroidism and mouse models with parathyroid defects have elucidated important roles for: transcription factors (e.g., TBX1, GATA3, GCMB, AIRE1, and SOX3), the tubulin-specific chaperone (TBCE), and the mitochondrial genome in determining parathyroid development; the calcium-sensing receptor (CaSR) and G-protein subunit α11 in regulating extracellular calcium and PTH secretion; and PTH gene expression for synthesis and secretion of PTH. Moreover, recombinant PTH and drugs targeting the CaSR have been shown to be of benefit for the management of hypoparathyroidism.