Familial Hypocalciuric Hypercalcemia - Causes

Causes

Types include:

Most cases are associated with loss of function mutations in the CASR gene, which encodes a calcium-sensing receptor, expressed in parathyroid and kidney tissue. The perceived lack of calcium levels by the parathyroid leads to constitutively high levels of parathyroid hormone, and therefore hypercalcemia. Functionally, parathyroid hormone (PTH) (aka parathormone or parathyrin) increases calcium resorption from the bone and increases phosphate excretion from the kidney which increases serum calcium and decreases serum phosphate.

Another form has been associated with chromosome 3q.