Therapeutic management of congenital forms of endocrine hypertension.

Congenital forms of endocrine hypertension are rare and potentially life-threatening disorders, primarily caused by genetic defects affecting adrenal steroid synthesis and activation pathways. These conditions exhibit diverse clinical manifestations, which can be distinguished by their unique molecular mechanisms and steroid profiles. Timely diagnosis and customized management approach are crucial to mitigate unfavorable outcomes associated with uncontrolled hypertension and other related conditions. Treatment options for these disorders depend on the distinct underlying pathophysiology, which involves specific pharmacological therapies or surgical adrenalectomy in some instances. This review article summarizes the current state of knowledge on the therapeutic management of congenital forms of endocrine hypertension, focusing on familial hyperaldosteronism (FH), congenital adrenal hyperplasia, apparent mineralocorticoid excess, and Liddle syndrome. We provide an overview of the genetic and molecular pathogenesis underlying each disorder, describe the clinical features, and discuss the various therapeutic approaches available and their risk of adverse effects, aiming to improve outcomes in patients with these rare and complex conditions.

Hipopotasemia e hipertensión arterial: es importante no infravalorarlas / Hypokalemia and arterial hypertension: it is important not to underestimate them

El síndrome de exceso aparente de mineralocorticoides es un trastorno autosómico recesivo caracterizado por hipertensión e hipopotasemia. Hay menos de 100 casos descritos en el mundo, debidos a mutaciones en el gen HSD11B2 (16q22). Clínicamente se caracteriza por poliuria y polidipsia de inicio habitualmente en primera infancia, fallo de medro e hipertensión arterial grave, con niveles bajos de renina y aldosterona, hipopotasemia, alcalosis metabólica y nefrocalcinosis. El pronóstico es malo, pudiendo fallecer los pacientes por secuelas de hipertensión arterial grave (accidentes cerebrovasculares, insuficiencia cardiaca y renal). Sin embargo, el pronóstico con tratamiento adecuado parece ser bueno (AU)

Apparent mineralcorticoid excess syndrome is an autosomal recessive disorder characterized by hypertension and hypokalemia. There are less than 100 cases described in the world, due to mutations in the HSD11B2 gene (16q22). Clinically it is characterized by polyuria and polydipsia with onset usually in early childhood, failure to thrive and severe arterial hypertension, with low renin and aldosterone levels, hypokalemia, metabolic alkalosis and nephrocalcinosis. The prognosis is poor, with the possibility of death due to sequelae of severe arterial hypertension (stroke, heart failure and renal failure). However, the prognosis with adequate treatment appears to be good. (AU)

Apparent mineralocorticoid excess: A diagnosis beyond classical causes of severe hypertension in a child.

A genetic defect of 11 ß-hydroxysteroid dehydrogenase causes apparent mineralocorticoid excess syndrome. Since 50 days of life, our patient was hospitalized several times for various reasons including hypokalemia. At the age of 3.3 years, she was diagnosed with severe hypertension (160/120 mmHg). She also had left ventricular hypertrophy and hypertensive retinopathy and referred to our center. Her renal function and electrolytes were normal except for hypokalemia. She was on captopril treatment; nifedipine and propranolol were added. Plasma renin and aldosterone concentrations were 1.13 pg/ml (1-8.2 pg/ml) and 12.2 ng/dl (35-300 ng/dl), respectively. Severe hypertension, hypokalemia, low renin and aldosterone levels pointed to the diagnosis of apparent mineralocorticoid excess syndrome. Strict salt-restricted diet and potassium citrate were ordered. Genetic analysis of the HSD11B2 gene showed c.623G>A (p.Arg208His). Spironolactone was initiated. On follow-up, amiloride was added and her blood pressure was controlled. In patients with severe HSD11B2 mutation, combination therapy of spironolactone with amiloride could be effective in controlling blood pressure.

Clinical, Biochemical, and Genetic Characteristics of "Nonclassic" Apparent Mineralocorticoid Excess Syndrome.

Context: Classical apparent mineralocorticoid excess (AME) is a rare recessive disorder, caused by severe 11ß-hydroxysteroid dehydrogenase type 2 enzyme (11ß-HSD2) deficiency. AME manifests as low-renin pediatric hypertension, hypokalemia and high cortisol/cortisone (F/E) ratio. Objective: To evaluate nonclassic AME (NC-AME) due to partial 11ß-HSD2 insufficiency and its association with hypertension, mineralocorticoid receptor (MR) activation, and inflammatory parameters. Design: Cross-sectional study. Setting: Primary care cohort. Participants: We recruited 127 adolescents and adults. Subjects with secondary hypertension were excluded. We measured clinical, biochemical, renal, vascular, and inflammatory variables. Sequencing of HSD11B2 gene was performed in all subjects. Main Outcome Measure: NC-AME. Results: Serum F/E ratio was positively associated with systolic blood pressure (BP), microalbuminuria, and high-sensitivity C-reactive protein (hs-CRP). Serum cortisone correlated with MR activation parameters even when adjusted for age, body mass index, and sex: lower cortisone with higher potassium excretion (partial r = -0.29, P = 0.002) and with lower plasma renin activity (PRA) (partial r = 0.29, P = 0.001). Consistently, we identified 9 in 127 subjects (7.1%) with high F/E ratios (first quartile) and low cortisone (last quartile), suggestive of NC-AME. These subjects had higher systolic BP, 141.4 ± 25.7 mm Hg vs 127.3 ± 18.1 mm Hg, P = 0.03; lower PRA, 0.36 ± 0.19 ng/L*s vs 0.64 ± 0.47 ng/L*s, P < 0.0001; and greater potassium excretion, microalbuminuria, hs-CRP, and plasminogen activator inhibitor. We only found in 2 out of 9 subjects with NC-AME heterozygous mutations in the HSD11B2 gene. Conclusions: These findings suggest a spectrum of partial 11ß-HSD2 insufficiency in a primary care cohort without the classic phenotype and genotype of AME. NC-AME may represent a phenotype of MR activation and cardiovascular risk, suggesting that these subjects could be treated with MR antagonists.

Serum Cortisol and Cortisone as Potential Biomarkers of Partial 11ß-Hydroxysteroid Dehydrogenase Type 2 Deficiency.

BACKGROUND: Pathogenic variations in HSD11B2 gene triggers the apparent mineralocorticoid excess syndrome (AME). There is scarce information regarding the phenotypes of subjects carrying heterozygous pathogenic variants in HSD11B2 gene. We investigated if serum cortisol/cortisone (F/E) ratio and cortisone are useful for identifying partial 11ßHSD2 deficiency in those heterozygous subjects. METHODS: We studied two patients diagnosed with AME and their families carrying either D223N or R213C mutation. We also evaluated 32 healthy control subjects (13 children and 19 adults) to obtain normal references ranges for all measured variables. Case 1: A boy carrying D223N mutation in HSD11B2 gene and Case 2: A girl carrying R213C mutation. We assessed serum F/E ratio and cortisone by HPLC-MS/MS, aldosterone, plasma-renin-activity(PRA), electrolytes, and HSD11B2 genetic analyses. RESULTS: The normal values (median [interquartile range]) in children for serum F/E and cortisone (µg/dl) were 2.56 [2.21-3.69] and 2.54 [2.35-2.88], and in adults were 4.42 [3.70-4.90] and 2.23 [1.92-2.57], respectively. Case 1 showed a very high serum F/E 28.8 and low cortisone 0.46 µg/dl. His mother and sister were normotensives and heterozygous for D223N mutation with high F/E (13.2 and 6.0, respectively) and low cortisone (2.0 and 2.2, respectively). Case 2 showed a very high serum F/E 175 and suppressed cortisone 0.11 µg/dl. Her parents and sister were heterozygous for the R213C mutation with normal phenotype, but high F/E and low cortisone. Heterozygous subjects showed normal aldosterone, PRA, but lower fractional excretion of sodium and urinary Na/K ratio than controls. CONCLUSION: Serum F/E ratio and cortisone allow to identify partial 11ßHSD2 deficiencies, as occurs in heterozygous subjects, who would be susceptible to develop arterial hypertension.

Posaconazole-Induced Pseudohyperaldosteronism.

A woman in her late 60s with disseminated histoplasmosis was treated with posaconazole because first-line therapies were not tolerated. She subsequently presented with decompensated heart failure, hypertension, and hypokalemia. Laboratory tests revealed low renin and aldosterone levels. A potential mechanism is inhibition of the enzyme 11ß-hydroxysteroid dehydrogenase 2, with resultant apparent mineralocorticoid excess.

Liquorice-induced apparent mineralocorticoid excess presenting in the emergency department.

A 65-year-old woman with a background of myalgic encephalitis, who was taking alternative medicines and dietary supplements, presented with hypokalaemia and hypertension. After a thorough history it became apparent that this was most likely secondary to regular consumption of liquorice tea. The patient was advised to discontinue drinking this tea and was discharged. Follow-up showed normalising blood pressure and hypokalaemia, with a normal aldosterone:renin ratio.

Apparent mineralocorticoid excess.

Apparent mineralocorticoid excess is a syndrome reflecting the absent or impaired activity of the enzyme 11ß-hydroxysteroid dehydrogenase Type 2. It may be mild when the mutant enzyme retains some activity, or severe when activity is absolutely or essentially absent. Diagnosis relies on a triad of hypertension, hypokalemia and suppressed plasma aldosterone levels, plus an abnormal urinary cortisol to cortisone ratio, either free steroid or metabolites. Treatment is symptomatic in the mild form - correction of hypertension and hypokalemia - but needs to be prompt, vigorous and sustained in the severe form, which usually presents in neonates/infancy. Elucidation of the pathogenesis of apparent mineralocorticoid excess is an example of 'reverse translation', in that it proved prismatic for the demonstration of the physiologic mechanisms underlying the selective activation of epithelial mineralocorticoid receptors by aldosterone.

Pseudohipoaldosteronismo y aparente exceso de mineralocorticoides: cara y ceca en dos pacientes pediátricos / Pseudohypoaldosteronism and apparent mineralocorticoid excess: two faces, two pediatric patients

Los síndromes endocrinológicos con hipofunción o hiperfunción con niveles paradójicos de dosajes hormonales han sido bien caracterizados en los últimos años del siglo XX, a partir del desarrollo de técnicas genéticas y moleculares. Presentamos dos pacientes con pseudohipoaldosteronismo y aparente exceso de mineralocorticoides como síndromes en espejo, con la intención de alertar al médico clínico respecto de su consideración como entidad diagnóstica en niños con alteraciones hidroelectrolíticas. (AU)

Endocrinological syndromes with underactive or overactive hormonal levels with paradoxical dosages have been well characterized over the years of the twentieth century, from the development of genetic and molecular techniques. We present two patients with pseudohypoaldosteronism and apparent mineralocorticoid excess as mirror syndromes, with the aim to alert the clinician regarding their consideration as a diagnostic entity in children with fluid and electrolyte disturbances. (AU)

Inherited forms of mineralocorticoid hypertension.

Aldosterone plays an essential role in the maintenance of fluid and electrolyte homeostasis in the distal nephron. Monogenic forms of mineralocorticoid hypertension result from genetic defects leading to excessive production of aldosterone (or other mineralocorticoids) from the adrenal cortex or to illegitimate mineralocorticoid effects in the kidney. They are characterized in the majority of cases by early onset, severe or resistant hypertension and associated with suppressed renin levels. Depending on their causes, these diseases are distinguished at the clinical and biochemical level and differently affect aldosterone levels and kalemia. The diagnosis is confirmed by genetic testing, which allows in many cases targeted treatment to prevent severe cardiovascular consequences of high blood pressure or aldosterone excess. In this review we describe the different forms of inherited mineralocorticoid hypertension, providing an overview of their clinical and biochemical features, their underlying genetic defects and specific therapeutic options.

Genetic disorders of potassium homeostasis.

Hereditary disorders of potassium homeostasis are an interesting group of disorders, affecting people from the newborn period to adults of all ages. The clinical presentation varies from severe hypotension at birth to uncontrolled hypertension in adults, often associated with abnormal potassium values, although many patients may have a normal serum potassium concentration despite being affected by the genetic disorder. A basic understanding of these disorders and their underlying mechanisms has significant clinical implications, especially in the few patients with subtle clinical signs and symptoms. We present a summary of these disorders, with emphasis on the clinical presentation and genetic mechanisms of these disorders.

Apparent mineralocorticoid excess (AME) syndrome.

Apparent mineralocorticoid excess (AME) syndrome is a rare autosomal recessive disorder due to the deficiency of 11b hydroxysteroid dehydrogenase type 2 enzyme (11beta-HSD2). Mutations in this gene affect the enzymatic activity resulting to an excess of cortisol, which causes its inappropriate access to mineralocorticoid receptor leading to inherited hypertension.This is a potentially fatal but treatable disorder. We present clinical and molecular studies on two sisters diagnosed as AME.

Monogenic forms of hypertension.

Arterial hypertension in childhood is less frequent as compared to adulthood but is more likely to be secondary to an underlying disorder. After ruling out more obvious causes, some patients still present with strongly suspected secondary hypertension of yet unknown etiology. A number of these children have hypertension due to single gene mutations inherited in an autosomal dominant or recessive fashion. The finding of abnormal potassium levels (low or high) in the presence of suppressed renin secretion, and metabolic alkalosis or acidosis should prompt consideration of these familial diseases. However, mild hypertension and the absence of electrolyte abnormalities do not exclude hereditary conditions. In monogenic hypertensive disorders, three distinct mechanisms leading to the common final pathway of increased sodium reabsorption, volume expansion, and low plasma renin activity are documented. The first mechanism relates to gain-of-function mutations with a subsequent hyperactivity of renal sodium and chloride reabsorption leading to plasma volume expansion (e.g., Liddle's syndrome, Gordon's syndrome). The second mechanism involves deficiencies of enzymes that regulate adrenal steroid hormone synthesis and deactivation (e.g., subtypes of congenital adrenal hyperplasia, apparent mineralocorticoid excess (AME)). The third mechanism is characterized by excessive aldosterone synthesis that escapes normal regulatory mechanisms and leading to volume-dependent hypertension in the presence of suppressed renin release (glucocorticoid remediable aldosteronism). Hormonal studies coupled with genetic testing can help in the early diagnosis of these disorders.

Apparent mineralocorticoid excess syndrome: report of one family with three affected children.

The syndrome of apparent mineralocorticoid excess (AME) is an autosomal recessive disorder characterized by hypertension, hypokalemia, low renin, and hypoaldosteronism. It is caused by deficiency of 11ß-hydroxysteroid dehydrogenase, which results in a defect of the peripheral metabolism of cortisol to cortisone. As a consequence, the serum cortisol half-life (T½) is prolonged, ACTH is suppressed, and serum cortisol concentration is normal. The hormonal diagnosis of the disorder is made by the increased ratio of urine-free cortisol to cortisone. In patients with AME, this ratio is 5-18, while in normal individuals it is <0.5. These studies suggest that an abnormality in cortisol action or metabolism results in cortisol behaving as a potent mineralocorticoid and causing the syndrome of AME. We report three siblings - two female and one male - with the syndrome of apparent mineralocorticoid excess who presented with hypertension, hypokalemia, low renin, and low aldosterone levels. The finding of abnormally high ratios of 24-h urine-free cortisol to cortisone in our three patients (case 1, 8.4; case 2, 25; and case 3, 7.5) confirmed the diagnosis of apparent mineralocorticoid excess syndrome in these children. They were treated with oral potassium supplements. The addition of spironolactone resulted in a decrease in blood pressure, rise in serum potassium and a gradual increase in plasma renin activity in all three. In this study, the genetic testing of those three siblings with the typical clinical features of AME has detected missense mutation c.662C>T (p.Arg208Cys) in exon 3 of the HSD11B2 gene in the homozygous state.

Apparent mineralocorticoid excess: time of manifestation and complications despite treatment.

Here we describe the case of a patient followed from birth because of a positive family history for apparent mineralocorticoid excess (AME) in an older brother. The patient, a girl, had normal serum electrolyte and blood pressure measurements in the first months after birth. Not until the age of 11 months did she develop anorexia and failure to thrive in combination with hypertension, hypokalemia, and metabolic alkalosis, which are consistent with the diagnosis of AME. This diagnosis was confirmed by mutation analysis of the HSD11B2 gene (C1228T). Treatment with amiloride and furosemide electrolyte disturbances normalized her blood pressure. At the age of 19 years she unexpectedly suffered a stroke. Additional investigations revealed no accepted risk factor for stroke. We discuss the possible underlying mechanisms for the delayed manifestation of hypertension and electrolyte disturbances in AME, propose an additional explanation for the stroke in this patient, and advise treatment with a mineralocorticoid receptor antagonist to reduce stroke risk in patients with AME.

Inherited forms of mineralocorticoid hypertension.

PURPOSE OF REVIEW: Inherited forms of mineralocorticoid hypertension are a group of monogenic disorders that, although rare, have enlightened our understanding of normal physiology, and subsequent processes implicated in the pathogenesis of 'essential' hypertension. They often present in early life and can be a cause of major morbidity and mortality that can be effectively treated with simple but targeted pharmacological therapy. Interestingly, all the conditions centre on the regulation of sodium transport through its epithelial channel, either directly or through mediators that act via the mineralocorticoid receptor. RECENT FINDINGS: In recent years, molecular mechanisms of these conditions and their functional consequences have been elucidated. Diagnosis has been facilitated by plasma and urinary biomarkers. SUMMARY: We provide an overview and diagnostic approach to apparent mineralocorticoid excess, glucocorticoid remediable aldosteronism, familial hyperaldosteronism type 2, Liddle's syndrome, Gordon's syndrome, activating mutations of the mineralocorticoid receptor, generalized glucocorticoid resistance and hypertensive forms of congenital adrenal hyperplasia.

Secondary nephrogenic diabetes insipidus as a complication of inherited renal diseases.

BACKGROUND/AIMS: Nephrogenic diabetes insipidus (NDI) is a serious condition with large water losses in the urine and the risk of hypernatremic dehydration. Unrecognized, repeated episodes of hypernatremic dehydration can lead to permanent brain damage. Primary NDI is due to mutations in either AVPR2 or AQP2. NDI can also occur as a secondary complication, most commonly from obstructive uropathy or chronic lithium therapy. We observed NDI in patients with inherited tubulopathies and aimed to define the clinical and molecular phenotype. METHODS: We reviewed the medical notes of 4 patients with clinical NDI and an underlying molecularly confirmed diagnosis of nephropathic cystinosis, Bartter syndrome, nephronophthisis and apparent mineralocorticoid excess, respectively. RESULTS: The patients all failed to concentrate their urine after administration of 1-desamino[8-D-arginine] vasopressin. None had an identifiable mutation in AVPR2 or AQP2, consistent with secondary NDI. Patients experienced repeated episodes of hypernatremic dehydration, and in 2 cases, NDI was initially thought to be the primary diagnosis, delaying recognition of the underlying problem. CONCLUSION: The recognition of this potential complication is important as it has direct implications for clinical management. The occurrence of NDI in association with these conditions provides clues for the etiology of aquaporin deficiency.

11ß-Hydroxysteroid dehydrogenase type-2 and type-1 (11ß-HSD2 and 11ß-HSD1) and 5ß-reductase activities in the pathogenia of essential hypertension.

Cortisol availability is modulated by several enzymes: 11ß-HSD2, which transforms cortisol (F) to cortisone (E) and 11ß-HSD1 which predominantly converts inactive E to active F. Additionally, the A-ring reductases (5α- and 5ß-reductase) inactivate cortisol (together with 3α-HSD) to tetrahydrometabolites: 5αTHF, 5ßTHF, and THE. The aim was to assess 11ß-HSD2, 11ß-HSD1, and 5ß-reductase activity in hypertensive patients. Free urinary F, E, THF, and THE were measured by HPLC-MS/MS in 102 essential hypertensive patients and 18 normotensive controls. 11ß-HSD2 enzyme activity was estimated by the F/E ratio, the activity of 11ß-HSD1 in compare to 11ß-HSD2 was inferred by the (5αTHF + 5ßTHF)/THE ratio and 5ß-reductase activity assessed using the E/THE ratio. Activity was considered altered when respective ratios exceeded the maximum value observed in the normotensive controls. A 15.7% of patients presented high F/E ratio suggesting a deficit of 11ß-HSD2 activity. Of the remaining 86 hypertensive patients, two possessed high (5αTHF + 5ßTHF)/THE ratios and 12.8% had high E/THE ratios. We observed a high percentage of alterations in cortisol metabolism at pre-receptor level in hypertensive patients, previously misclassified as essential. 11ß-HSD2 and 5ß-reductase decreased activity and imbalance of 11ß-HSDs should be considered in the future management of hypertensive patients.