Hereditary hyperparathyroidism syndromes.

Primary hyperparathyroidism is a common endocrine disorder, resulting from a persistent hypercalcemia along with an inadequate secretion of parathyroid hormone. In approx 95\% of cases, it occurs sporadically; rarely, it is part of familial syndromes. These inherited syndromes typically present at an earlier age than the nonheritable form and occur with equal frequencies in both sexes. The differential diagnosis is often difficult, but it is of fundamental importance for the management of patients and their family. The availability of specific genetic tests has improved the diagnostic accuracy allowing early diagnosis in asymptomatic family members. Before the advent of genetic testing, a definitive diagnosis could be made only in symptomatic cases based on clinical data and family history.