Familial and Hereditary Forms of Primary Hyperparathyroidism

Individuals with a familial predisposition to the development of parathyroid tumors constitute a small minority of all patients with primary hyperparathyroidism (PHPT). These familial syndromes exhibit Mendelian inheritance patterns and the main causative genes in most families have been identified. They include multiple endocrine neoplasia (MEN; types 1, 2A, and 4), hyperparathyroidism-jaw tumor (HPT-JT) syndrome, familial isolated hyperparathyroidism, familial hypocalciuric hypercalcemia (FHH), and neonatal severe PHPT. Each MEN type is associated with the various combinations of specific tumors. MEN1 is characterized by the occurrence of parathyroid, enteropancreatic, and pituitary tumors; MEN2A is characterized by medullary thyroid carcinoma and pheochromocytoma, and MEN4 is characterized by a pathological spectrum similar to that of MEN1 in association with tumors of the adrenal, kidney, and reproductive organs. HPT-JT is characterized by PHPT, ossifying fibromas of maxillary bones, kidney disease, and uterine neoplasias. The prompt diagnosis of these diseases is of great importance for planning appropriate surveillance of the mutant carriers and correct surgical management. The search for mutation is also useful for the identification of the family members who do not carry the mutation and can avoid unnecessary biochemical and instrumental evaluations. Surgery remains the treatment of choice in all familial forms except FHH.