PRKAR1A and Cushing syndrome: Germline inactivating variants in <i>PRKAR1A</i> are associated with <i>Carney complex and primary pigmented nodular adrenocortical disease (PPNAD).</i> Furthermore, germline alterations in phosphodiesterases such as <i>PDE11A</i> and <i>PDE8B</i>, which impair cAMP degradation, have been associated with Cushing syndrome and micronodular adrenal hyperplasia.