Novel mutation of the calcium sensing receptor gene in familial hypocalciuric hypercalcaemia and neonatal severe hyperparathyroidism.

摘要

Familial hypocalciuric hypercalcaemia (FHH) and neonatal severe hyperparathyroidism (NSHPT) are caused by inactivating mutations of the CASR gene.1 FHH is a condition exhibiting mild to moderate hypercalcaemia, which is generally asymptomatic, normal serum levels of PTH (but not suppressed) and a low rate of urinary calcium excretion best demonstrated by measuring the ratio of urinary clearance of calcium to creatinine (< 0-01). NSHPT is a disorder of newborn infants, exhibiting hypotonia and poor feeding, as well as multiple fractures of long bones. Severe hypercalcaemia is present in affected infants and markedly elevated PTH levels result in skeletal abnormalities.