MEN1 and familial isolated hyperparathyroidism: Moreover, mutational and/or epigenetic silencing of other genes predisposing for FIHP and MEN1-like syndromes have also been detected in small subsets of apparent sporadic parathyroid adenomas, including CDKN1A, CDKN1B, CDKN2A, CDKN2B, CDKN2C, and GCM2 [53, 58–60].