In most of the reported cases, the genetic panel was extended by the analysis of the genes associated with hyperparathyroidism, i.e., MEN1 (encoding the tumour suppressor protein menin; MEN1, Multiple Endocrine Neoplasia type 1), CaSR (encoding the G protein-coupled extracellular calcium-sensing receptor), HRPT2 (encoding the tumour suppressor parafibromin) and CDK (encoding the tumour suppressor cyclin-dependent kinase) (37, 48, 49). Here, MEN1 is linked to hyperparathyroidism.