Genetics of Cortisol-Secreting Bilateral Macro- and Micronodular Adrenal Hyperplasias

Bilateral adrenal cortex hyperplasias can present in various forms and are divided as either macronodular or micronodular. This review presents the recent identifications of the genetic alterations responsible for the various forms of cortisol-secreting adrenal hyperplasias. These include the tumor suppressor genes ARMC5 in bilateral primary macronodular adrenal hyperplasia (PBMAH) and KDM1A in GIP-dependent PBMAH with Cushing’s syndrome. Other genetic alterations are found in PBMAH associated with rare syndromic forms and various cAMP/PKA pathway gene mutations are involved in both macronodular and micronodular adrenal hyperplasias. We present as well certain clinical recommendations for each genetic etiology, including that ARMC5 or KDM1A genetic testing should be offered to all patients with PBMAH, depending on the Cushing syndrome’s GIP-dependence or not.