calcaemia: a review

Hypercalcaemia is frequently found during routine blood screening and often remains asymptomatic for a prolonged period until serious renal or bone complications reveal its presence.'2 Symptoms of hypercalcaemia also may be marked by nonspecific gastrointestinal or neuropsychiatric complaints. It is therefore not unexpected that routine serum calcium analysis by auto-analyser techniques is frequently the first hint for a correct diagnosis. Although the list of causes of hypercalcaemia is long, the vast majority are due either to primary hyperparathyroidism or malignancy.3 In most situations, a correct clinical history and examination with simple measurements of serum calcium, phosphorus, chloride, bicarbonate, and creatinine are usually insufficient to predict the correct diagnosis with high probability. Serum parathyroid hormone estimation is often essential for distinguishing primary hyperparathyroidism from malignancy unless the cause of malignancy is clear. Since many of these hypercalcaemic patients ultimately are considered candidates for parathyroidectomy, a correct diagnosis is required. This is especially true for patients with familial forms of hypercalcaemia, since when this familial hypercalcaemia is attributed to parathyroid adenoma or hyperplasia, surgical correction is possible, while on the contrary, these interventions have usually no success in familial benign hypercalcaemia4 or familial hypocalciuric hypercalcaemia (FHH).5'6 The latter syndrome is clearly different from hyperparathyroidism, either occurring as an isolated abnormality or in the context of familial multiple endocrine neoplasia and has to be ruled out in patients presenting with hypercalcaemia. This short review will focus on different aspects of familial hypercalcaemia.