| Genetics of calcium disorders
|
| The calcium-sensing receptor (CaSR) is pivotal in regulating responses to alterations in calcium and genetic abnormalities altering CaSR function result in both hyper and hypocalcaemia. In subjects heterozygous for an inactivating mutation of the CaSR a state of relative 'resistance' to the effects of ionized calcium exists producing a condition known as familial hypocalciuric hypercalcaemia (FHH). Homozygous inactivating mutations cause neonatal severe hyperparathyroidism (NSHPT) which can be fatal if parathyroidectomy is not performed in early life. When an activating mutation of the CaSR is present, varying degrees of hypocalcaemia are observed depending on the severity of the mutation and this accounts for some of the cases of familial hypocalcaemia described.
|
|
