Familial Hypocalciuric Hypercalcaemia	
	
Familial hypocalciuric hypercalcaemia is an autosomal dominant condition that is frequently found in patients with a history of unsuccessful surgery for primary hyperparathyroidism. The characteristics of this condition are a family history in siblings or offspring, low renal excretion of calcium (<l00mg/24h up to 2.5mmol/24h) and magnesium, and usually little or no symptomatology. This condition is also referred to as familial benign hypercalcaemia. Patients need to be identified since they have a very poor response to parathyroidectomy. Unlike familial forms of primary hyperparathyroidism, hypercalcaemia and hypocalciuria are present from the neonatal period. In contrast, primary hyperparathyroidism associated with MEN syndromes is rarely evident before the age of ten.