- A condition due to diminution or absence of the secretion of the parathyroid hormones, with low serum calcium and tetany, and sometimes with increased bone density. SEE ALSO: pseudohypoparathyroidism. SYN: parathyroid insufficiency.- familial h. inherited isolated h. characterized by hypocalcemia, hyperphosphatemia, cataracts, intracerebral calcifications, and tetany; all three mendelian forms (sex-linked, autosomal dominant and recessive) of inheritance are known [MIM*146200, MIM*241400, and MIM*307700]. The autosomal dominant form is caused by mutation in either the parathyroid hormone gene (PTH) on chromosome 11p or the calcium sensing receptor gene (CASR) on 3q.
* * *hy·po·para·thy·roid·ism -.par-ə-'thī-.rȯid-.iz-əm n deficiency of parathyroid hormone in the body also the resultant abnormal state marked by low serum calcium and a tendency to chronic tetany
* * *n.subnormal activity of the parathyroid glands, causing a fall in the blood concentration of calcium and muscular spasms (see tetany).
* * *hy·po·para·thy·roid·ism (hi″po-par″ə-thiґroid-iz-əm) the condition produced by greatly reduced function of the parathyroid glands; it may be due to autoimmune disease, genetic factors, or the removal of the glands. Lack of parathyroid hormone leads to a fall in plasma calcium level (hypocalcemia), which may result in increased neuromuscular excitability and ultimately tetany, as well as a rise in plasma phosphate level. Bone turnover is reduced; there may also be dermatologic, ophthalmologic (cataracts), psychiatric, and dental symptoms, and associated primary failure of other endocrine glands such as the adrenal cortex. See also pseudohypoparathyroidism. Called also parathyroid insufficiency.
Medical dictionary. 2011.