CDKN1B and parathyroid gland carcinoma: Indications for genetic testing for inheritable parathyroid disease include patientsyounger than 30 years old with PHPT; those with multigland disease on imaging orhistory; those with a family history of hypercalcemia or syndromic disease such asMEN1, MEN2A, MEN4 or hyperparathyroidism–jaw tumor syndrome and those withatypical parathyroid adenoma and parathyroid carcinoma (7).