Genetic causes of primary aldosteronism

Unmasking primary aldosteronism: Transforming disease management with advanced steroid profiling

Primary aldosteronism (PA) is traditionally thought to result from the overproduction of aldosterone which is unregulated by the renin-angiotensin system. It leads to a significantly increased risk of cardiovascular and metabolic complications as compared to primary hypertension. However, approximately one-third of patients diagnosed with PA according to the traditional guidelines have been found to exhibit low aldosterone levels and other steroid hormones may also play a potentially critical role in PA development. Early diagnosis of PA remains challenging due to low screening rates and the complex diagnostic procedures. The need for invasive adrenal vein sampling for PA subtyping also leads to a dilemma in therapeutic strategy selection. With advances in techniques, an increasing number of steroid hormones have been discovered to be associated with PA, potentially optimizing the PA diagnostic procedures. Herein, we review the cutting-edge advances in steroid hormones, including aberrant hormone synthesis and metabolism related to the pathophysiological development of PA, quantitative assays, and potential clinical value. Mass spectrometry provides a robust technical foundation for the simultaneous profiling of a panel of steroid hormones. Steroid hormone profiling combined with machine learning algorithms holds great research promise for facilitating early diagnosis and minimally invasive subtyping of PA. Thus, current progress and future expectations in combining steroid hormones with advanced technologies for early disease diagnosis and management are also reviewed. Research Agenda. 1) Identify changes in steroid hormones and the underlying biochemical mechanisms associated with PA. 2) Investigate the role of advanced mass spectrometry techniques in steroid hormone profiling. 3) Discuss current advances and future expectations in combining machine learning algorithms with MS-based steroid hormone profiling for PA's systematic and practical management.

High prevalence of primary aldosteronism in a tertiary care hospital in Lebanon

Primary aldosteronism (PA) is a frequent cause of secondary hypertension. Studies on the prevalence of PA are lacking in the Middle East region. To determine the proportion of patients with high aldosterone-to-renin ratio (ARR) among Lebanese patients with hypertension screened for PA and to compare their clinical and biological characteristics with patients with essential hypertension. A retrospective review of medical charts of patients with hypertension undergoing sampling of serum aldosterone and plasma renin concentration at a tertiary care center between October 2022 and 2023 was conducted. Of 144 patients with hypertension screened for PA, 23 (16%) had an ARR higher than 3.7 ng/dL/mU/L and serum aldosterone above 15 ng/dL. The mean age of the screened population was 51 ± 15 years, 56% were men. The median duration of hypertension was 4 years and the median number was 2 of antihypertensive medications. Patients with a positive screening test were mostly men (88%, P = .0001), and more frequently had diabetes (50%, P < .0001) than those with essential hypertension. Only 22% had hypokalemia. Of the 23 patients, 11 underwent intravenous saline suppression testing; PA was confirmed in all of them. The high frequency of PA in our center is comparable to other countries. More studies are needed to determine how to reduce healthcare disparities and overcome the barriers to appropriate diagnosis and treatment.

Evolutionary Characteristics in Primary Aldosteronism Patients

BACKGROUND

Primary aldosteronism is predominantly caused by excessive aldosterone production from the adrenal cortex, and the aldosterone-producing structures could take many forms, like adenomas, nodules, micronodules, and so on. Most studies of primary aldosteronism were limited to the hotspot driver genes responsible for autonomous aldosterone production; however, the panoramic genetic architecture and genomic alterations of aldosterone-producing structures and their adjacent hyperplasia glands remain unknown.

METHODS

In this study, whole-exome sequencing and transcriptome sequencing (RNA-seq) analyses were performed using functional nodules and matched hyperplasia tissues, which were microdissected guided by aldosterone synthase immunohistochemistry. Phylogenetic trees were constructed based on the shared and unique mutations, gene mutation spectrums, and clonal characteristics.

RESULTS

The rates of mutations represented higher means of functional nodules than hyperplasia samples, and the little mutational overlap was shown between the 2 groups on phylogenetic trees. The mutations of the aldosterone driver gene (KCNJ5 or CACNA1D) were only observed in functional nodules and indicated almost the largest values of cancer cell fraction. Moreover, the functional nodules also harbored some potential variants related to cell proliferation, which were not detected in hyperplasia tissues. Transcriptome analysis suggested that only 25.5% upregulated and 23.3% downregulated genes overlapped between functional nodules and hyperplasia tissues.

CONCLUSIONS

This study demonstrated a genetic and transcriptome landscape of aldosterone-producing structures and adjacent hyperplasia glands in primary aldosteronism. The results indicated independent clonal origins on functional nodules and hyperplasia tissues, and little mutual evolutionary relationship was found on their phylogenetic trees.

E3 ubiquitin ligase TRIM2 identified as a novel suppressor of CYP11B2 and aldosterone production

Aldosterone-producing adenoma (APA) is a leading cause of primary aldosteronism (PA), a condition marked by excessive aldosterone secretion. CYP11B2, the aldosterone synthase, plays a critical role in aldosterone biosynthesis and the development of APA. Despite its significance, encoding regulatory mechanisms governing CYP11B2, particularly its degradation, remain poorly understood. In this study, we sought to uncover novel regulators of CYP11B2 stability by conducting a siRNA screen targeting E3 ubiquitin ligases. Our results identified TRIM2 as a key negative regulator of CYP11B2, where its overexpression led to a significant reduction in CYP11B2 protein levels and a concomitant decrease in aldosterone production in adrenal tumor cells. Mechanistically, we demonstrated that TRIM2 interacts with CYP11B2 via its RBCC domain, promoting K29/48-linked polyubiquitination and destabilization of CYP11B2. Further results revealed that TRIM2 is downregulated in APA tissues, showing differential expression between the zona glomerulosa (ZG) and zona fasciculata (ZF) of normal adrenal tissue. These findings highlight TRIM2 as a novel modulator of aldosterone synthesis through CYP11B2 degradation, offering a potential therapeutic target for APA.

An In Silico Investigation of the Pathogenic G151R G Protein-Gated Inwardly Rectifying K+ Channel 4 Variant to Identify Small Molecule Modulators

Primary aldosteronism is characterised by the excessive production of aldosterone, which is a key regulator of salt metabolism, and is the most common cause of secondary hypertension. Studies have investigated the association between primary aldosteronism and genetic alterations, with pathogenic mutations being identified. This includes a glycine-to-arginine substitution at position 151 (G151R) of the G protein-activated inward rectifier potassium (K+) channel 4 (GIRK4), which is encoded by the KCNJ5 gene. Mutations in GIRK4 have been found to reduce the selectivity for K+ ions, resulting in membrane depolarisation, the activation of voltage-gated Ca2+ channels, and an increase in aldosterone secretion. As a result, there is an interest in identifying and exploring the mechanisms of action of small molecule modulators of wildtype (WT) and mutant channels. In order to investigate the potential modulation of homotetrameric GIRK4WT and GIRK4G151R channels, homology models were generated. Molecular dynamics (MD) simulations were performed, followed by a cluster analysis to extract starting structures for molecular docking. The central cavity has been previously identified as a binding site for small molecules, including natural compounds. The OliveNetTM database, which consists of over 600 compounds from Olea europaea, was subsequently screened against the central cavity. The binding affinities and interactions of the docked ligands against the GIRK4WT and GIRK4G151R channels were then examined. Based on the results, luteolin-7-O-rutinoside, pheophorbide a, and corosolic acid were identified as potential lead compounds. The modulatory activity of olive-derived compounds against the WT and mutated forms of the GIRK4 channel can be evaluated further in vitro.

Clinical value of 68Ga-pentixafor PET/CT in patients with primary aldosteronism and bilateral lesions: preliminary results of a single-centre study

BACKGROUND

Subtype diagnosis of primary aldosteronism (PA) is used to determine treatment, and the potential utility of 68Ga-pentixafor PET/CT for investigation of PA has long been recognized. The study aimed to evaluate the clinical value of 68Ga-pentixafor PET/CT in the diagnosis and prognosis of patients with bilateral lesions identified by CT.

METHODS

In total, 25 patients with PA and bilateral lesions on CT were retrospectively evaluated. All patients underwent 68Ga-Pentixafor PET/CT and adrenal vein sampling. The analysis focused on establishing the relationship between bilateral adrenal lesions SUVmax and the ratio of bilateral adrenal lesions SUVmax (CON) and clinical diagnosis, treatment outcomes, and KCNJ5 gene status.

RESULTS

The concordance rate between 68Ga-Pentixafor PET/CT and adrenal venous sampling was 65.2% (15/23). The lateralization results of 68Ga-pentixafor PET/CT supported the clinical decisions of 20 patients with PA, 90% of whom showed effectiveness in treatment. The SUVmax on the dominant side of the surgically treated patients was higher than that of patients treated with drugs. The SUVmax of the KCNJ5 mutant group was higher than that of the KCNJ5 wild group, and 68Ga-Pentixafor uptake was correlated with KCNJ5 gene status.

CONCLUSIONS

68Ga-Pentixafor PET/CT proves beneficial for patients with PA with bilateral lesions on CT. The treatment is generally effective based on the results of PET lateralization. Simultaneously, a certain relationship exists between 68Ga-Pentixafor PET/CT and KCNJ5 gene status, warranting further analysis.

Screening and diagnosis of primary aldosteronism. Consensus document of all the Spanish Societies involved in the management of primary aldosteronism

Primary aldosteronism (PA) is the most frequent cause of secondary hypertension (HT), and is associated with a higher cardiometabolic risk than essential HT. However, PA remains underdiagnosed, probably due to several difficulties clinicians usually find in performing its diagnosis and subtype classification. The aim of this consensus is to provide practical recommendations focused on the prevalence and the diagnosis of PA and the clinical implications of aldosterone excess, from a multidisciplinary perspective, in a nominal group consensus approach by experts from the Spanish Society of Endocrinology and Nutrition (SEEN), Spanish Society of Cardiology (SEC), Spanish Society of Nephrology (SEN), Spanish Society of Internal Medicine (SEMI), Spanish Radiology Society (SERAM), Spanish Society of Vascular and Interventional Radiology (SERVEI), Spanish Society of Laboratory Medicine (SEQC(ML)), Spanish Society of Anatomic-Pathology, Spanish Association of Surgeons (AEC).

What We Know about and What Is New in Primary Aldosteronism

Primary aldosteronism (PA), a significant and curable cause of secondary hypertension, is seen in 5-10% of hypertensive patients, with its prevalence contingent upon the severity of the hypertension. The principal aetiologies of PA include bilateral idiopathic hypertrophy (BIH) and aldosterone-producing adenomas (APAs), while the less frequent causes include unilateral hyperplasia, familial hyperaldosteronism (FH) types I-IV, aldosterone-producing carcinoma, and ectopic aldosterone synthesis. This condition, characterised by excessive aldosterone secretion, leads to augmented sodium and water reabsorption alongside potassium loss, culminating in distinct clinical hallmarks: elevated aldosterone levels, suppressed renin levels, and hypertension. Notably, hypokalaemia is present in only 28% of patients with PA and is not a primary indicator. The association of PA with an escalated cardiovascular risk profile, independent of blood pressure levels, is notable. Patients with PA exhibit a heightened incidence of cardiovascular events compared to counterparts with essential hypertension, matched for age, sex, and blood pressure levels. Despite its prevalence, PA remains frequently undiagnosed, underscoring the imperative for enhanced screening protocols. The diagnostic process for PA entails a tripartite assessment: the aldosterone/renin ratio (ARR) as the initial screening tool, followed by confirmatory and subtyping tests. A positive ARR necessitates confirmatory testing to rule out false positives. Subtyping, achieved through computed tomography and adrenal vein sampling, aims to distinguish between unilateral and bilateral PA forms, guiding targeted therapeutic strategies. New radionuclide imaging may facilitate and accelerate such subtyping and localisation. For unilateral adrenal adenoma or hyperplasia, surgical intervention is optimal, whereas bilateral idiopathic hyperplasia warrants treatment with mineralocorticoid antagonists (MRAs). This review amalgamates established and emerging insights into the management of primary aldosteronism.

Treating Primary Aldosteronism-Induced Hypertension: Novel Approaches and Future Outlooks

Primary aldosteronism (PA) is the most common cause of secondary hypertension and is associated with increased morbidity and mortality when compared with blood pressure-matched cases of primary hypertension. Current limitations in patient care stem from delayed recognition of the condition, limited access to key diagnostic procedures, and lack of a definitive therapy option for nonsurgical candidates. However, several recent advances have the potential to address these barriers to optimal care. From a diagnostic perspective, machine-learning algorithms have shown promise in the prediction of PA subtypes, while the development of noninvasive alternatives to adrenal vein sampling (including molecular positron emission tomography imaging) has made accurate localization of functioning adrenal nodules possible. In parallel, more selective approaches to targeting the causative aldosterone-producing adrenal adenoma/nodule (APA/APN) have emerged with the advent of partial adrenalectomy or precision ablation. Additionally, the development of novel pharmacological agents may help to mitigate off-target effects of aldosterone and improve clinical efficacy and outcomes. Here, we consider how each of these innovations might change our approach to the patient with PA, to allow more tailored investigation and treatment plans, with corresponding improvement in clinical outcomes and resource utilization, for this highly prevalent disorder.

Cross-Disciplinary Approach of Adrenal Tumors: Insights into Primary Aldosteronism-Related Mineral Metabolism Status and Osteoporotic Fracture Risk

Our objective was to overview the novel aspects in the field of adrenal gland neoplasms, namely, the management of bone status with respect to primary aldosteronism (PA). In the current narrative review, a PubMed study was conducted from inception until June 2023. The inclusion criteria were: human (clinically relevant) studies of any study design (at least 10 patients per study); English papers; and the following combination of key words within the title and/or abstract: "aldosterone" AND "bone", "skeleton", "osteoporosis", "fracture", "calcium", "parathyroid", "DXA", "osteocalcin", "P1NP", "alkaline phosphatase", "bone marker", "trabecular bone score", or "FRAX". The exclusion criteria were in vitro or animal studies, reviews, and case reports/series. We screened 1027 articles and finally included 23 studies (13 of case-control type, 3 cross-sectional, 5 prospective, 1 observational cohort, and 1 retrospective study). The assessments provided in these studies were as follows: nine studies addressed Dual-Energy X-ray Absorptiometry (DXA), another study pointed out a bone microarchitecture evaluation underlying trabecular bone score (TBS), and seven studies investigated the bone turnover markers (BTMs) profile. Moreover, 14 studies followed the subjects after adrenalectomy versus medical treatment, and 21 studies addressed secondary hyperparathyroidism in PA patients. According to our study on published data during a period of almost 40 years (n = 23, N = 3965 subjects aged between 38 and 64, with a mean age 56.75, and a female-to-male ratio of 1.05), a higher PTH in PA versus controls (healthy persons or subjects with essential hypertension) is expected, secondary hyperparathyroidism being associated in almost half of the adults diagnosed with PA. Additionally, mineral metabolism anomalies in PA may include lower serum calcium and higher urinary calcium output, all these three parameters being reversible under specific therapy for PA, regardless medical or surgical. The PA subgroup with high PTH seems at higher cardiovascular risk, while unilateral rather than bilateral disease was prone to this PTH anomaly. Moreover, bone mineral density (BMD) according to central DXA might show a higher fracture risk only in certain adults, TBS being a promising alternative (with a still unknown perspective of diabetes' influence on DXA-TBS results in PA). However, an overall increased fracture prevalence in PA is described in most studies, especially with respect to the vertebral site, the fracture risk that seems correctable upon aldosterone excess remission. These data recommend PA as a cause of secondary osteoporosis, a treatable one via PA intervention. There is still an area of debate the way to address BMTs profile in PA, the case's selection toward specific bone evaluation in every day practice, and further on, the understanding of the potential genetic influence at the level of bone and mineral complications in PA patients.

Aldosterone: Renal Action and Physiological Effects

Aldosterone exerts profound effects on renal and cardiovascular physiology. In the kidney, aldosterone acts to preserve electrolyte and acid-base balance in response to changes in dietary sodium (Na+ ) or potassium (K+ ) intake. These physiological actions, principally through activation of mineralocorticoid receptors (MRs), have important effects particularly in patients with renal and cardiovascular disease as demonstrated by multiple clinical trials. Multiple factors, be they genetic, humoral, dietary, or otherwise, can play a role in influencing the rate of aldosterone synthesis and secretion from the adrenal cortex. Normally, aldosterone secretion and action respond to dietary Na+ intake. In the kidney, the distal nephron and collecting duct are the main targets of aldosterone and MR action, which stimulates Na+ absorption in part via the epithelial Na+ channel (ENaC), the principal channel responsible for the fine-tuning of Na+ balance. Our understanding of the regulatory factors that allow aldosterone, via multiple signaling pathways, to function properly clearly implicates this hormone as central to many pathophysiological effects that become dysfunctional in disease states. Numerous pathologies that affect blood pressure (BP), electrolyte balance, and overall cardiovascular health are due to abnormal secretion of aldosterone, mutations in MR, ENaC, or effectors and modulators of their action. Study of the mechanisms of these pathologies has allowed researchers and clinicians to create novel dietary and pharmacological targets to improve human health. This article covers the regulation of aldosterone synthesis and secretion, receptors, effector molecules, and signaling pathways that modulate its action in the kidney. We also consider the role of aldosterone in disease and the benefit of mineralocorticoid antagonists. © 2023 American Physiological Society. Compr Physiol 13:4409-4491, 2023.

Likely Pathogenic Variants of Cav1.3 and Nav1.1 Encoding Genes in Amyotrophic Lateral Sclerosis Could Elucidate the Dysregulated Pain Pathways

Amyotrophic lateral sclerosis (ALS) is a lethal multisystem neurodegenerative disease associated with progressive loss of motor neurons, leading to death. Not only is the clinical picture of ALS heterogenous, but also the pain sensation due to different types of pain involvement. ALS used to be considered a painless disease, but research has been emerging and depicting a more complex pain representation in ALS. Pain has been detected even a couple years before the symptomatic stage of ALS, referring to primary pain associated with muscle denervation, although secondary pain due to nociceptive causes is also a part of the clinical picture. A new non-contact dying-back injury mechanism theory of ALS recently postulated that the irreversible intrafusal proprioceptive Piezo2 microinjury could be the primary damage, with underlying genetic and environmental risk factors. Moreover, this Piezo2 primary damage is also proposed to dysregulate the primary pain pathways in the spinal dorsal horn in ALS due to the lost imbalanced subthreshold Ca2+ currents, NMDA activation and lost L-type Ca2+ currents, leading to the lost activation of wide dynamic range neurons. Our investigation is the first to show that the likely pathogenic variants of the Cav1.3 encoding CACNA1D gene may play a role in ALS pathology and the associated dysregulation or loss of the pain sensation. Furthermore, our reanalysis also shows that the SCN1A gene might also contribute to the dysregulated pain sensation in ALS. Finally, the absence of pathogenic variants of Piezo2 points toward the new non-contact dying-back injury mechanism theory of ALS. However, molecular and genetic investigations are needed to identify the functionally diverse features of this proposed novel critical pathway.

Recurrence of Primary Aldosteronism After Surgery in Aldosterone-producing Adenoma With KCNJ5 Gene Mutation

Primary aldosteronism (PA) is a major cause of secondary hypertension. Aldosterone-producing adenoma (APA) is a subtype of PA, and adrenalectomy is the gold-standard treatment. Recently, a high prevalence of the KCNJ5 gene mutation has been reported in APA, particularly in Japan. Herein, we present 2 extremely rare cases of PA recurrence more than 10 years after adrenalectomy for APA. In the first case, a 52-year-old woman was examined for hypertension 22 years after total adrenalectomy of the right adrenal gland. Recurrent PA was diagnosed based on high aldosterone-renin-ratio (ARR), identification of left adrenal gland tumor by computed tomography (CT), and a confirmatory test. In the second case, a 65-year-old man was examined for hypertension 17 years after total adrenalectomy of the left adrenal gland. He had maintained his blood pressure using medication since the onset of hypertension 4 years after the surgery. A year later, a high ARR was observed. PA recurrence was determined by a right adrenal gland tumor noted on CT and a confirmatory test. Somatic mutations in KCNJ5 were detected in the resected tissues in both cases. We recommend careful follow-ups after adrenalectomy in APA cases, especially in those with a KCNJ5 gene mutation.

Update on the Genetics of Primary Aldosteronism and Aldosterone-Producing Adenomas

PURPOSE OF THE REVIEW

Primary aldosteronism (PA) is the leading cause of secondary hypertension, accounting for over 10% of patients with high blood pressure. It is characterized by autonomous production of aldosterone from the adrenal glands leading to low-renin levels. The two most common forms arise from bilateral adrenocortical hyperplasia (BAH) and aldosterone-producing adenoma (APA). We discuss recent discoveries in the genetics of PA.

RECENT FINDINGS

Most APAs harbor variants in the KCNJ5, CACNA1D, ATP1A1, ATP2B3, and CTNNB1 genes. With the exception of β-catenin (CTNNB1), all other causative genes encode ion channels; pathogenic variants found in PA lead to altered ion transportation, cell membrane depolarization, and consequently aldosterone overproduction. Some of these genes are found mutated in the germline state (CYP11B2, CLCN2, KCNJ5, CACNA1H, and CACNA1D), leading then to familial hyperaldosteronism, and often BAH rather than single APAs. Several genetic defects in the germline or somatic state have been identified in PA. Understanding how these molecular abnormalities lead to excess aldosterone contributes significantly to the elucidation of the pathophysiology of low-renin hypertension. It may also lead to new and more effective therapies for this disease acting at the molecular level.

Monogenic forms of low-renin hypertension: clinical and molecular insights

Monogenic disorders of hypertension are a distinct group of diseases causing dysregulation of the renin-angiotensin-aldosterone system and are characterized by low plasma renin activity. These can chiefly be classified as causing (i) excessive aldosterone synthesis (familial hyperaldosteronism), (ii) dysregulated adrenal steroid metabolism and action (apparent mineralocorticoid excess, congenital adrenal hyperplasia, activating mineralocorticoid receptor mutation, primary glucocorticoid resistance), and (iii) hyperactivity of sodium and chloride transporters in the distal tubule (Liddle syndrome and pseudohypoaldosteronism type 2). The final common pathway is plasma volume expansion and catecholamine/sympathetic excess that causes urinary potassium wasting; hypokalemia and early-onset refractory hypertension are characteristic. However, several single gene defects may show phenotypic heterogeneity, presenting with mild hypertension with normal electrolytes. Evaluation is based on careful attention to family history, physical examination, and measurement of blood levels of potassium, renin, and aldosterone. Genetic sequencing is essential for precise diagnosis and individualized therapy. Early recognition and specific management improves prognosis and prevents long-term sequelae of severe hypertension.

Divergent Characteristics of T-Cell Receptor Repertoire Between Essential Hypertension and Aldosterone-Producing Adenoma

Aldosterone-producing adenoma (APA) is a benign adrenal tumor that results in persistent hyperaldosteronism. As one major subtype of primary aldosteronism, APA leads to secondary hypertension that is associated with immune dysregulation. However, how the adaptive immune system, particularly the T-cell population, is altered in APA patients remains largely unknown. Here, we performed TCR sequencing to characterize the TCR repertoire between two age-matched groups of patients: one with APA and the other one with essential hypertension (EH). Strikingly, we found a significant reduction of TCR repertoire diversity in the APA group. Analyses on TCR clustering and antigen annotation further showed that the APA group possessed lower diversity in TCR clonotypes with non-common antigen-specific features, compared with the EH group. In addition, our results indicated that the strength of correlation between generation probabilities and frequencies of TCR clonotypes was significantly higher in the APA group than that in the EH group. Finally, we observed that clinical features, including plasma aldosterone level, aldosterone–renin ratio, and blood sodium level, were positively associated with the strength of correlation between generation and abundance of TCR clonotypes in the APA group. Our findings unveiled the correlation between T-cell immune repertoire and APA, suggesting a critical role of such adrenal adenoma in the T-cell immunity of patients with hypertension.

Genetic Alterations in Benign Adrenal Tumors

The genetic basis of most types of adrenal adenomas has been elucidated over the past decade, leading to the association of adrenal gland pathologies with specific molecular defects. Various genetic studies have established links between variants affecting the protein kinase A (PKA) signaling pathway and benign cortisol-producing adrenal lesions. Specifically, genetic alterations in GNAS, PRKAR1A, PRKACA, PRKACB, PDE11A, and PDE8B have been identified. The PKA signaling pathway was initially implicated in the pathogenesis of Cushing syndrome in studies aiming to understand the underlying genetic defects of the rare tumor predisposition syndromes, Carney complex, and McCune-Albright syndrome, both affected by the same pathway. In addition, germline variants in ARMC5 have been identified as a cause of primary bilateral macronodular adrenal hyperplasia. On the other hand, primary aldosteronism can be subclassified into aldosterone-producing adenomas and bilateral idiopathic hyperaldosteronism. Various genes have been reported as causative for benign aldosterone-producing adrenal lesions, including KCNJ5, CACNA1D, CACNA1H, CLCN2, ATP1A1, and ATP2B3. The majority of them encode ion channels or pumps, and genetic alterations lead to ion transport impairment and cell membrane depolarization which further increase aldosterone synthase transcription and aldosterone overproduction though activation of voltage-gated calcium channels and intracellular calcium signaling. In this work, we provide an overview of the genetic causes of benign adrenal tumors.

[Immunogenetics of primary hyperaldosteronism: fundamental studies and their clinical prospects]

Primary hyperaldosteronism (PHA) is the most common form of endocrine hypertension. Until recently, the reason for the development of this condition was believed to be the presence of genetic mutations, however, many studies declare that the disease can be polyetiologic, be the result of genetic mutations and autoimmune triggers or cell clusters of aldosterone-producing cells diffusely located in the adrenal gland at the zona glonerulosa, zona fasculata, zona reticularis, as well as directly under the adrenal capsule. Recently, the actions of autoantibodies to type 1 angiotensin II receptors have been described in patients with renal transplant rejection, with preeclampsia, and with primary hyperaldosteronism. The diagnostic role of antibodies in both forms of PHA (aldosterone-producing adenoma and bilateral hyperaldosteronism) requires clarification. Diagnosis and confirmation of the focus of aldosterone hypersecretion is a multi-stage procedure that requires a long time and economic costs. The relevance of timely diagnosis of primary hyperaldosteronism is to reduce medical and social losses. This work summarizes the knowledge about genetic mutations and presents all the original studies devoted to autoantibodies in PHA, as well as discusses the diagnostic capabilities and limitations of the available methods of primary and differential diagnosis of the disease and the prospects for therapy.

Genetics of Primary Aldosteronism

Primary aldosteronism is considered the commonest cause of secondary hypertension. In affected individuals, aldosterone is produced in an at least partially autonomous fashion in adrenal lesions (adenomas, [micro]nodules or diffuse hyperplasia). Over the past decade, next-generation sequencing studies have led to the insight that primary aldosteronism is largely a genetic disorder. Sporadic cases are due to somatic mutations, mostly in ion channels and pumps, and rare cases of familial hyperaldosteronism are caused by germline mutations in an overlapping set of genes. More than 90% of aldosterone-producing adenomas carry somatic mutations in K⁺ channel Kir3.4 (KCNJ5), Ca²⁺ channel Ca_V1.3 (CACNA1D), alpha-1 subunit of the Na⁺/K⁺ ATPase (ATP1A1), plasma membrane Ca²⁺ transporting ATPase 3 (ATP2B3), Ca²⁺ channel Ca_V3.2 (CACNA1H), Cl⁻ channel ClC-2 (CLCN2), β-catenin (CTNNB1), and/or G-protein subunits alpha q/11 (GNAQ/11). Mutations in some of these genes have also been identified in aldosterone-producing (micro)nodules, suggesting a disease continuum from a single cell, acquiring a somatic mutation, via a nodule to adenoma formation, and from a healthy state to subclinical to overt primary aldosteronism. Individual glands can have multiple such lesions, and they can occur on both glands in bilateral disease. Familial hyperaldosteronism, typically with early onset, is caused by germline mutations in steroid 11-beta hydroxylase/ aldosterone synthase (CYP11B1/2), CLCN2, KCNJ5, CACNA1H, and CACNA1D.

Pathophysiology and histopathology of primary aldosteronism

Primary aldosteronism (PA) can be sporadic or familial and classified into unilateral and bilateral forms. Sporadic PA predominates with excessive aldosterone production usually arising from a unilateral aldosterone-producing adenoma (APA) or bilateral adrenocortical hyperplasia. Familial PA is rare and caused by germline variants, that partly correspond to somatic alterations in APAs. Classification into unilateral and bilateral PA determines the treatment approach but does not accurately mirror disease pathology. Some evidence indicates a disease continuum ranging from balanced aldosterone production from each adrenal to extreme asymmetrical bilateral aldosterone production. Nonetheless, surgical removal of the overactive adrenal in unilateral PA achieves highly successful outcomes and almost all patients are biochemically cured of their aldosteronism.

Characteristics of a Novel ATP2B3 K416_F418delinsN Mutation in a Classical Aldosterone-Producing Adenoma

Simple Summary

The ATP2B3 channel mutation is a rare cause of primary aldosteronism (PA). ATP2B3 gene mutation leads to the dysfunction of calcium channel that pumps calcium ion out of the cell and accumulates intracellular calcium signal to stimulate aldosterone synthesis. In the present study, we found a novel somatic ATP2B3 K416_F418delinsN mutation in a PA patient, and proved its functionality by demonstrating aldosterone hyper-function in the mutant-transfected adrenal cell-line. The ATP2B3 K416_F418delinsN mutation resulted from the deletion from nucleotides 1248 to 1253. The translated amino acid sequence from 416 to 418 as lysine-phenylalanine-phenylalanine was deleted and an asparagine was inserted due to the merging of residual nucleotide sequences.

Abstract

In patients with primary aldosteronism (PA), the prevalence of ATP2B3 mutation is rare. The aim of this study is to report a novel ATP2B3 mutation in a PA patient. Based on our tissue bank of aldosterone-producing adenomas (APA), we identified a novel somatic ATP2B3 K416_F418delinsN mutation. The affected individual was a 53 year-old man with a 4 year history of hypertension. Computed tomography (CT) showed bilateral adrenal masses of 1.6 (left) and 0.5 cm (right) in size. An adrenal venous sampling (AVS) showed a lateralization index (LI) of 2.2 and a contralateral suppression index (CLS) of 0.12; indicating left functional predominance. After a left unilateral adrenalectomy, he achieved partial biochemical and hypertension–remission. This classical adenoma harbored a novel ATP2B3 K416_F418delinsN somatic mutation, which is a deletion from nucleotides 1248 to 1253. The translated amino acid sequence from 416 to 418, reading as lysine-phenylalanine-phenylalanine, was deleted; however, an asparagine was inserted due to merging of residual nucleotide sequences. The CYP11B2 immunohistochemistry staining demonstrated strong immunoreactivity in this classical adenoma. The ATP2B3 K416_F418delinsN mutation is a functional mutation in APA, since HAC15 cells, a human adrenal cell line, transfected with the mutant gene showed increased CYP11B2 expression and aldosterone production.

Novel Mutations Detection with Next-Generation Sequencing and Its Association with Clinical Outcome in Unilateral Primary Aldosteronism

Somatic mutations have been identified in adrenal tissues of unilateral primary aldosteronism (uPA). The spectrum of somatic mutations in uPAs was investigated using a customized and targeted next-generation sequencing (cNGS) approach. We also assessed whether cNGS or Sanger sequencing-identified mutations have an association with clinical outcomes in uPA. Adrenal tumoral tissues of uPA patients who underwent adrenalectomy were obtained. Conventional somatic mutation hotspots in 240 extracted DNA samples were initially screened using Sanger sequencing. A total of 75 Sanger-negative samples were further investigated by sequencing the entire coding regions of the known aldosterone-driver genes by our cNGS gene panel. Somatic mutations in aldosterone-driver genes were detected in 21 (28%) of these samples (8.8% of all samples), with 9 samples, including mutations in CACNA1D gene (12%), 5 in CACNA1H (6.6%), 3 in ATP2B3 (4%), 2 in CLCN2 (2.6%), 1 in ATP1A1 (1.3%), and 1 in CTNNB1 (1.3%). Via combined cNGS and Sanger sequencing aldosterone-driver gene mutations were detected in altogether 186 of our 240 (77.5%) uPA samples. The complete clinical success rate of patients containing cNGS-identified mutations was higher than those without mutations (odds ratio (OR) = 10.9; p = 0.012). Identification of somatic mutations with cNGS or Sanger sequencing may facilitate the prediction of complete clinical success after adrenalectomy in uPA patients.

A Chinese pedigree with glucocorticoid remediable aldosteronism

Glucocorticoid-remediable aldosteronism (GRA) is an autosomal-dominant inherited aldosteronism that is often accompanied by early-onset hypertension. GRA is caused by the unequal crossover of the 11β-hydroxylase (CYP11B1) and aldosterone synthase (CYP11B2) genes. As a result of chimeric gene duplication, aldosterone is ectopically synthesized in the adrenal zona fasciculata under the control of adrenocorticotropic hormone (ACTH). Here, we describe a Chinese pedigree with three affected subjects. Both the uncle and nephew were hospitalized in our hospital due to early-onset hypertension (onset <20 years old) and were diagnosed with primary aldosteronism (PA). Their laboratory test results revealed hyperaldosteronism, hyporeninemia, a high plasma aldosterone to renin (ARR) ratio, and normal serum potassium (K⁺). Captopril failed to suppress aldosterone secretion. This family had a strong paternal history of hypertension. Thirteen members underwent gene testing, and three of them were found to be GRA positive. Through long-extension PCR (XL-PCR) and direct sequencing, we identified the CYP11B1/CYP11B2 chimeric gene, and with unequal crossover breakpoints located between intron 2 of CYP11B1 and exon 3 of CYP11B2 in the three patients. Low-dose dexamethasone was effective. This is the first family report of GRA in northern China. Moreover, a case of GRA combined with a CACNA1H gene mutation is reported for the first time. We found that dihydropyridine calcium channel blockers (CCBs) combined with aldosterone receptor antagonists exerted good therapeutic effects in controlling blood pressure in GRA patients for whom glucocorticoid therapy was not an option.

Aldosterone-producing adenoma-harbouring KCNJ5 mutations is associated with lower prevalence of metabolic disorders and abdominal obesity

OBJECTIVE

Aldosterone overproduction and lipid metabolic disturbances between idiopathic hyperaldosteronism (IHA) and unilateral aldosterone-producing adenoma (APA) have been inconsistently linked in patients with primary aldosteronism. Moreover, KCNJ5 mutations are prevalent among APAs and enhance aldosterone synthesis in adrenal cortex. We aimed to investigate the prevalence of metabolic syndrome (MetS) in each primary aldosteronism subtype and observe the role of KCNJ5 mutations among APAs on the distribution of abdominal adipose tissues quantified using computed tomography (CT), including their changes postadrenalectomy.

DESIGN AND METHODS

We retrospectively collected 244 and 177 patients with IHA and APA at baseline. Patients with APA had undergone adrenalectomy, and gene sequencing revealed the absence (n = 75) and presence (n = 102) of KCNJ5 mutations. We also recruited 31 patients with APA who had undergone CT-scan 1-year postadrenalectomy.

RESULTS

The patients with APA harbouring KCNJ5 mutations had significantly lower prevalence of MetS and smaller distribution in waist circumference, subcutaneous adipose tissue (SAT), and visceral adipose tissue (VAT) than the other groups. Logistic regression analysis indicated that the VAT area correlated significantly with KCNJ5 mutations among the APAs. Only participants with KCNJ5 mutations had significant increases in triglycerides, cholesterol, SAT, and VAT after 1-year postadrenalectomy.

CONCLUSION

This study is the first to demonstrate that MetS and abdominal obesity were less prevalent in the patients with APA harbouring KCNJ5 mutations compared with the IHA group and the non-KCNJ5-mutated APA group. Increasing prevalence of dyslipidaemia and abdominal obesity was observed in patients with KCNJ5 mutations 1-year postadrenalectomy.

Primary Aldosteronism: a Continuum from Normotension to Hypertension

PURPOSE OF REVIEW

Primary aldosteronism (PA) is the most common cause of secondary hypertension. Emerging evidence suggests that PA is associated with cardiovascular, metabolic, and renal complications, that likely develop insidiously, due to prolonged inappropriate mineralocorticoid receptor activation. In this review, we discuss the expanding clinical and pathological spectrum of PA.

RECENT FINDINGS

Clinical and molecular studies conducted over the recent years reveal that PA traverses a series of contiguous stages. Pre-clinical, but hormonally overt PA has been identified in patients with normal blood pressure, and such patients harbor an increased risk of developing hypertension. Similarly, genetic and histopathological advancements have exposed a spectrum of PA pathology that corresponds to a continuum that spans from pre-clinical stages to florid PA. PA evolves from pre-hypertensive stages to resistant hypertension, along with serious cardiovascular and renal consequences. Early recognition of PA and targeted therapy will be essential for cardiovascular morbidity and mortality prevention in a large number of patients.

Chronic kidney disease in adrenal disorders

PURPOSE OF REVIEW

This review will focus on hypertension due to underlying adrenal disorders in chronic kidney disease (CKD). Diagnosis of adrenal hypertension and particularly primary aldosteronism (PA) in CKD is frequently not pursued. We outline limitations that advanced kidney disease poses on the diagnostic work up of these disorders and provide a framework for approaching CKD patients suspected of having an adrenal disorder. Recognition of these disorders is important as they are often underdiagnosed which leads to poorer outcomes.

RECENT FINDINGS

Adrenal disease associated with hypertension in CKD is most commonly due to PA whereas pheochromocytoma and Cushing's disease are important but less common. Diagnosis of these diseases is important as their identification leads to better blood pressure control and can possibly mitigate the risk of progression of CKD. Work up and treatment of PA has been shown to be safe and is associated with less antihypertensive medication requirement for the associated hypertension and slower progression of CKD.

SUMMARY

This chapter summarizes the importance of recognizing adrenal hypertension in CKD and reinforces the need for physicians to pursue these diagnoses in CKD patients as this is safe and improves both BP control and delays progression of CKD.

Genomics of hypertension: the road to precision medicine

The known genetic architecture of blood pressure now comprises >30 genes, with rare variants resulting in monogenic forms of hypertension or hypotension and >1,477 common single-nucleotide polymorphisms (SNPs) being associated with the blood pressure phenotype. Monogenic blood pressure syndromes predominantly involve the renin-angiotensin-aldosterone system and the adrenal glucocorticoid pathway, with a smaller fraction caused by neuroendocrine tumours of the sympathetic and parasympathetic nervous systems. The SNPs identified in genome-wide association studies (GWAS) as being associated with the blood pressure phenotype explain only approximately 27% of the 30-50% estimated heritability of blood pressure, and the effect of each SNP on the blood pressure phenotype is small. A paucity of SNPs from GWAS are mapped to known genes causing monogenic blood pressure syndromes. For example, a GWAS signal mapped to the gene encoding uromodulin has been shown to affect blood pressure by influencing sodium homeostasis, and the effects of another GWAS signal were mediated by endothelin. However, the majority of blood pressure-associated SNPs show pleiotropic associations. Unravelling these associations can potentially help us to understand the underlying biological pathways. In this Review, we appraise the current knowledge of blood pressure genomics, explore the causal pathways for hypertension identified in Mendelian randomization studies and highlight the opportunities for drug repurposing and pharmacogenomics for the treatment of hypertension.

Approach to the Patient with Primary Aldosteronism: Utility and Limitations of Adrenal Vein Sampling

Several studies over the past 3 decades document a higher prevalence of primary aldosteronism (PA) among hypertensive patients than generally presumed. PA exists as a spectrum from mild to severe aldosterone excess. Although a variety of PA subtypes exist, the 2 most common are aldosterone-producing adenomas (APAs) and bilateral hyperaldosteronism (BHA). The distinction is important, because APA-and other subtypes, with aldosterone production mostly from 1 adrenal-can be cured surgically, and BHA should be treated medically with mineralocorticoid-receptor antagonists (MRAs). The major shortcomings in the tailored management of patients with possible PA are the low rates of screening for case identification and the expensive and technically challenging imaging and interventional procedures required to distinguish APA from BHA, especially adrenal vein sampling (AVS). When AVS identifies an APA and allows the patient to be cured surgically, the procedure is of great value. In contrast, the patient with BHA is treated with MRA whether AVS is performed or not. Consequently, it is prudent to gauge how likely it is to benefit from imaging and AVS in each case prior to embarking on these studies. The explosion of information about PA in the past decade, including predictors of APA and of surgical benefit, are useful in limiting the evaluation for some patients with a positive PA screening test. This article will review our suggestions for approaching these patients in a pragmatic style, recognizing the limitations to even the best resources and facilities.

Molecular Genetic and Genomic Alterations in Cushing's Syndrome and Primary Aldosteronism

The genetic alterations that cause the development of glucocorticoid and/or mineralocorticoid producing benign adrenocortical tumors and hyperplasias have largely been elucidated over the past two decades through advances in genomics. In benign aldosterone-producing adrenocortical tumors and hyperplasias, alteration of intracellular calcium signaling has been found to be significant in aldosterone hypersecretion, with causative defects including those in KCNJ5, ATP1A1, ATP2B3, CACNA1D, CACNA1H, and CLCN2. In benign cortisol-producing adrenocortical tumors and hyperplasias abnormal cyclic adenosine monophosphate-protein kinase A signaling has been found to play a central role in tumorigenesis, with pathogenic variants in GNAS, PRKAR1A, PRKACA, PRKACB, PDE11A, and PDE8B being implicated. The role of this signaling pathway in the development of Cushing's syndrome and adrenocortical tumors was initially discovered through the study of the underlying genetic defects causing the rare multiple endocrine neoplasia syndromes McCune-Albright syndrome and Carney complex with subsequent identification of defects in genes affecting the cyclic adenosine monophosphate-protein kinase A pathway in sporadic tumors. Additionally, germline pathogenic variants in ARMC5, a putative tumor suppressor, were found to be a cause of cortisol-producing primary bilateral macronodular adrenal hyperplasia. This review describes the genetic causes of benign cortisol- and aldosterone-producing adrenocortical tumors.

[Molecular genetics of human hypertension]

A genetic influence on blood pressure was demonstrated more than 100 years ago and a simple Mendelian inheritance was initially presumed. Platt and Pickering conducted a lively debate on this topic. Platt favored the idea that a single gene or only a few genes were responsible for high blood pressure. Pickering presented research results, which supported the assumption that many genes exerted an influence on blood pressure. This was all in a period when it was not even known what genes were. Genome-wide association studies (GWAS) according to the Pickering model have identified > 500 blood pressure relevant gene loci, which are distributed over the whole genome. Each individual gene exerts only a small effect on blood pressure. The dark horses of hypertension research are the secondary causes. In pheochromocytoma, primary aldosteronism, Cushing's syndrome and even fibromuscular dysplasia (renovascular hypertension) the results indicate that a genetic cause regularly underlies secondary hypertension. This would therefore also partially confirm Platt's theory. In the meantime, a multitude of forms of hypertension have been described with a genetic inheritance according to Mendel. Each of these genetic variants exerts a considerable influence on blood pressure. A multitude of novel physiological mechanisms were explained by this. These findings will become therapeutically important. Therefore, it is incumbent upon clinicians to be optimally informed about these research results.

Rare functional missense variants in CACNA1H: What can we learn from Writer's cramp?

Writer's cramp (WC) is a task-specific focal dystonia that occurs selectively in the hand and arm during writing. Previous studies have shown a role for genetics in the pathology of task-specific focal dystonia. However, to date, no causal gene has been reported for task-specific focal dystonia, including WC. In this study, we investigated the genetic background of a large Dutch family with autosomal dominant‒inherited WC that was negative for mutations in known dystonia genes. Whole exome sequencing identified 4 rare variants of unknown significance that segregated in the family. One candidate gene was selected for follow-up, Calcium Voltage-Gated Channel Subunit Alpha1 H, CACNA1H, due to its links with the known dystonia gene Potassium Channel Tetramerization Domain Containing 17, KCTD17, and with paroxysmal movement disorders. Targeted resequencing of CACNA1H in 82 WC cases identified another rare, putative damaging variant in a familial WC case that did not segregate. Using structural modelling and functional studies in vitro, we show that both the segregating p.Arg481Cys variant and the non-segregating p.Glu1881Lys variant very likely cause structural changes to the Cav3.2 protein and lead to similar gains of function, as seen in an accelerated recovery from inactivation. Both mutant channels are thus available for re-activation earlier, which may lead to an increase in intracellular calcium and increased neuronal excitability. Overall, we conclude that rare functional variants in CACNA1H need to be interpreted very carefully, and additional studies are needed to prove that the p.Arg481Cys variant is the cause of WC in the large Dutch family.

ATP1A1 de novo Mutation-Related Disorders: Clinical and Genetic Features

Background: ATP1A1 encodes an α1 isoform of Na⁺/K⁺-ATPase, which is expressed abundantly in kidneys and central nervous system. ATP1A1 variants may cause Na⁺/K⁺-ATPase loss of function and lead to a wide spectrum of phenotypes. This study aims to summarize the clinical and genetic features of ATP1A1 de novo mutation-related disorders and explore the potential correlations between phenotypes and genotypes. Methods: We analyzed two new cases harboring novel de novo ATP1A1 variants and reviewed all reported cases. Results: Both our probands had developmental delay, patient 1 accompanied with sleep disorders, irritability, and patient 2 with refractory seizures. They each had a novel de novo heterozygous missense variant, c.2797G>A[p.Asp933Asn] (NM_000701) and c.2590G>A[p.Gly864Arg] (NM_000701) respectively. Four patients with de novo ATP1A1 variants have been reported in two previous papers. Among them, three patients had refractory seizures and one patient had complex hereditary spastic paraplegia (HSP). Therefore, all six patients had developmental delay, and four of them had epilepsy. All variants located in the transmembrane regions M3, M4, M7, and M8 of ATP1A1 protein. Four patients with mutations in M3 and M7 had more severe phenotypes, including developmental delay and epileptic encephalopathy, three of them with hypomagnesemia, whereas two patients with mutations in M4 and M8 had milder phenotypes, only with mild developmental delay, without seizures or hypomagnesemia. Correcting hypomagnesemia had not controlled those seizures. Conclusions: Two novel de novo ATP1A1 variants identified in two patients here enriched the genotypic and phenotypic spectrum of ATP1A1 mutation-related disorder. Our findings suggest that hypomagnesemia in this disorder might relate to more severe phenotype and indicate more severe Na⁺/K⁺-ATPase dysfunction. Variations in M3 and M7 transmembrane regions were related to more severe phenotype than those in M4 and M8, which suggested that variations in M3 and M7 might cause more severe ATP1A1 functional defect.

Molecular genetics of human hypertension

PURPOSE OF REVIEW

Genetic variance on blood pressure was shown about 100 years ago; a Mendelian inheritance was initially presumed. Platt and Pickering conducted a lively debate, whether blood pressure was inherited in a Mendelian fashion or whether the condition was polygenic. Genetic-hypertension research has appropriately followed both pathways.

RECENT FINDINGS

Genome-wide association studies, Pickering model, have identified more than 500 blood-pressure loci, the targets of which are waiting to be evaluated. Then, come the 'dark-horses' of hypertension, namely 'secondary' causes. These conditions have been remarkably elucidative including pheochromocytoma, primary aldosteronism, Cushing's syndrome, and even renovascular hypertension. All these conditions feature genetic causes. Finally, arrive the Platt followers. A plethora of Mendelian conditions located within the kidney are established. These syndromes involve increased sodium (as chloride) absorption in the distal nephron. Finally, nonsalt-dependent Mendelian forms involving the vascular directly have been described. Mechanistically, Mendelian forms have large effects on blood pressure and offer effective treatment targets.

SUMMARY

Which genetic models will bring us improved therapies? Ongoing studies will answer that question. It behooves the clinician to follow this dynamic area of research.

The Potential Role of Aldosterone-Producing Cell Clusters in Adrenal Disease

Primary aldosteronism (PA) is the most common cause of secondary hypertension. The hallmark of PA is adrenal production of aldosterone under suppressed renin conditions. PA subtypes include adrenal unilateral and bilateral hyperaldosteronism. Considerable progress has been made in defining the role for somatic gene mutations in aldosterone-producing adenomas (APA) as the primary cause of unilateral PA. This includes the use of next-generation sequencing (NGS) to define recurrent somatic mutations in APA that disrupt calcium signaling, increase aldosterone synthase (CYP11B2) expression, and aldosterone production. The use of CYP11B2 immunohistochemistry on adrenal glands from normal subjects, patients with unilateral and bilateral PA has allowed the identification of CYP11B2-positive cell foci, termed aldosterone-producing cell clusters (APCC). APCC lie beneath the adrenal capsule and like APA, many APCC harbor somatic gene mutations known to increase aldosterone production. These findings suggest that APCC may play a role in pathologic progression of PA. Herein, we provide an update on recent research directed at characterizing APCC and also discuss the unanswered questions related to the role of APCC in PA.

Adrenocortical tumorigenesis: Lessons from genetics

Advances in genomics over the past two decades have allowed for elucidation of the genetic alterations leading to the development of adrenocortical tumors and/or hyperplasias. These molecular changes were initially discovered through the study of rare familial tumor syndromes such as McCune-Albright Syndrome, Carney complex, Li-Fraumeni syndrome, and Beckwith-Wiedemann syndrome, with the identification of alterations in genes and molecular pathways that subsequently led to the discovery of aberrations in these or related genes and pathways in sporadic tumors. Genetic alterations in GNAS, PRKAR1A, PRKACA, PRKACB, PDE11A, and PDE8B, that lead to aberrant cyclic adenosine monophosphate-protein (cAMP) kinase A signaling, were found to play a major role in the development of benign cortisol-producing adrenocortical tumors and/or hyperplasias, whereas genetic defects in KCNJ5, ATP1A1, ATP2B3, CACNA1D, CACNA1H, and CLCN2 were implicated in the development of benign aldosterone-producing tumors and/or hyperplasias through modification of intracellular calcium signaling. Germline ARMC5 defects were found to cause the development of primary bilateral macronodular adrenocortical hyperplasia with glucocorticoid and/or mineralocorticoid oversecretion. Adrenocortical carcinoma was linked primarily to aberrant p53 signaling and/or Wnt-β-catenin signaling, as well as IGF2 overexpression, with frequent genetic alterations in TP53, ZNRF3, CTNNB1, and 11p15. This review focuses on the genetic underpinnings of benign cortisol- and aldosterone-producing adrenocortical tumors/hyperplasias and adrenocortical carcinoma.