[Calcium sensing receptor: physiology and pathology].

[familial hypocalciuric hypercalcemia]

Calcium is a major ion in human metabolism and its level is highly controlled . This regulation is performed via the Calcium Sensing Receptor , a discovery which ten years ago led to the explanation of a number of clinical disorders . The syndromes caused by CaSR abnormalities are characterized by hypercalcemia or hypocalcemia , associated with inappropriate calciuria . An underlying genetic or auto-immune cause may be demonstrated . High blood calcium levels linked to mutations of the CaSR gene lead to familial hypocalciuric hypercalcemia and the neonatal and non neonatal forms with severe hypercalcemic . Hypocalcemia determined by mutations in the CaSR gene include autosomal dominant hypocalcemia and its sporadic form . Another clinical presentation similar to Bartter syndrome has been reported . Auto-antibodies directed against CaSRs , seen in auto-immune diseases , can lead to similar clinical presentations . Finally , CaSR polymorphisms modulate the range of blood calcium levels . With diagnosis of these diseases deleterious therapeutics can be avoided . The discovery of this receptor has led to new therapeutic prospects such as calcimimetics for hyperthyroidism .