RESUMO
Primary aldosteronism is the most common form of endocrine hypertension. This disorder comprises both sporadic and familial forms. Four familial forms of primary aldosteronism (FH-I to FH-IV) have been described. FH-III is caused by germline mutations in KCNJ5, encoding the potassium channel Kir3.4 (also called GIRK4). These mutations alter the selectivity filter of the channel and lead to abnormal ion currents with loss of potassium selectivity, sodium influx and consequent increased intracellular calcium that causes excessive aldosterone biosynthesis. To date, eleven families have been reported, carrying six different mutations. Although the clinical features are variable, FH-III patients often display severe hyperaldosteronism with an early onset, associated with hypokalemia and diabetes insipidus-like symptoms. In most cases FH-III patients are resistant to pharmacological therapy and require bilateral adrenalectomy to control symptoms. In the present manuscript, we review the genetics and pathological basis of FH-III, the diagnostic work-up, clinical features and therapeutic management. Finally, we will describe a new case of FH-III of an Italian patient carrying a Gly151Arg mutation.
Assuntos
Canais de Potássio Corretores do Fluxo de Internalização Acoplados a Proteínas G/genética , Hiperaldosteronismo/genética , Humanos , Hiperaldosteronismo/terapia , Masculino , Pessoa de Meia-Idade , FenótipoRESUMO
Renin-angiotensin-aldosterone system (RAAS) is recognized as the main regulatory system of hemodynamics in man, and its derangements have a key role in the development and maintenance of arterial hypertension. Classification of the hypertensive states according to different patterns of renin and aldosterone levels ("RAAS profiling") allows the diagnosis of specific forms of secondary hypertension and may identify distinct hemodynamic subsets in essential hypertension. In this review, we summarize the application of RAAS profiling for the diagnostic assessment of hypertensive patients and discuss how the pathophysiological framework provided by RAAS profiling may guide therapeutic decision-making, especially in the context of uncontrolled hypertension not responding to multi-therapy.