Mutation testing for MEN1 should be considered for patients who have been diagnosed with two or more tumours associated with MEN1 and patients who exhibit clinical indications of MEN syndrome, such as the presence of multiple parathyroid adenomas before the age of 45 and recurrent hyperparathyroidism or multiple enter pancreatic NETs at any age and first-degree relatives of known MEN1 mutation carriers, irrespective of whether they display symptoms. This evidence concerns the gene MEN1 and hyperparathyroidism.