Bilateral Idiopathic Adrenal Hyperplasia: Genetics and Beyond

Bilateral adrenal hyperplasia currently accounts for up to 2 thirds of cases of primary aldosteronism. As such, it represents a major opportunity for targeted medical management as opposed to unilateral surgically correctable forms of the disease. Although the majority of cases of primary aldosteronism are sporadic, bilateral adrenal hyperplasia may occur in the context of familial hyperaldosteronism where it is associated with specific germline mutations. Over the past 5 years, impressive progress has been made in our understanding of the genetic basis underlying primary aldosteronism, allowing us to identify and characterize new familial forms of the disease and to understand the mechanisms involved in the formation of aldosterone producing adenoma. In contrast, our knowledge of the genetic contribution to the development of bilateral adrenal hyperplasia, and in a larger context, to renin and aldosterone levels in the general population, is still poor. This review summarizes our current knowledge on the genetics of bilateral adrenal hyperplasia and addresses some open questions to be addressed by future research. In particular, genome-wide association studies in large populations may provide clues to understanding the genetic susceptibility underlying the development of primary aldosteronism.