Hypoparathyroidism

Hypoparathyroidism is the inadequate secretion of parathyroid hormone (PTH) by the parathyroid gland.

Clinical Findings

The clinical picture of primary hypoparathyroidism is dominated by the hypocalcaemia (osteoporosis, tetany).

Diagnosis

Typical laboratory findings are hypocalcaemia and hyperphosphataemia due to the decreased parathyroid hormone level.

Differentials

Primary and secondary forms can be distinguished. The former is characterized by hypocalcemia, the latter shows elevated calcium levels. Furthermore genetic and acquired forms can be distinguished.

Pathogenesis

Familial hypoparathyroidism can be caused by gain-of-function mutation in the calcium sensing receptor gene. Despite hypocalcaemia the chief cells of the parathyroid gland cannot secrete the hormone because the receptor continuously signals elevated plasma calcium levels.

Management

The symptoms usually can be ameliorated by application of parathyroid hormone.

Systematic

Disorders of the parathyroid hormone system
	Humoral hypercalcemia of malignancy
	Hyperparathyroidism
	Hypoparathyroidism
		AP2S1
		CASR
		GCM2
		GNA11
		Hypoparathyroidism, sensorineural deafness, and renal dysplasia syndrome
			GATA3
		Hypoparathyroidism-retardation-dysmorphism syndrome
			TBCE
		Kenny-Caffey syndrome
			TBCE
		PTH
	Parathyroid adenoma
	Parathyroid carcinoma
	Pseudohyperparathyreoidism
	Pseudohypoparathyroidism