Prevalence and Clinical Correlates of Somatic Mutation in Aldosterone Producing Adenoma-Taiwanese population

Abstract

Primary aldosteronism (PA) is a common form of secondary hypertension and has significant cardiovascular consequences. Mutated channelopathy due to the activation of calcium channels has been recently described in aldosterone-producing adenoma (APA). The study involved 148 consecutive PA patients, (66 males; aged 56.3 ± 12.3years) who received adrenalectomy, and were collected from the Taiwan PA investigator (TAIPAI) group. A high rate of somatic mutation in APA was found (n = 91, 61.5%); including mutations in KCNJ5 (n = 88, 59.5%), ATP1A1 (n = 2, 1.4%), and ATP2B3 (n = 1, 0.7%); however, no mutations in CACNA1D were identified. Mutation-carriers were younger (<0.001), had lower Cyst C (p = 0.042), pulse wave velocity (p = 0.027), C-reactive protein (p = 0.042) and a lower rate of proteinuria (p = 0.031) than non-carriers. After multivariate adjustment, mutation carriers had lower serum CRP levels than non-carriers (p = 0.031. Patients with mutation also had a greater chance of recovery from hypertension after operation (p = 0.005). A high incidence of somatic mutations in APA was identified in the Taiwanese population. Mutationcarriers had lower CRP levels and a higher rate of cure of hypertension after adrenalectomy. This raises the possibility of using mutation screening as a tool in predicting long-term outcome after adrenalectomy.Primary aldosteronism (PA), characterized by the autonomous production of aldosterone, is a common potentially curable cause of secondary hypertension 1 . It affects 5-13% of patients with hypertension in specialized centers 2,3 . PA patients have a high incidence of cardiovascular events in comparison with essential hypertension (EH) patients 4,5 . Somatic mutations in the selectivity filter of the KCNJ5 channel in APA result in a loss of selectivity for potassium and the entry of sodium, resulting in membrane depolarization, calcium mobilization, increased CYP11B2 expression, and aldosteronism 6 . Further exome sequencing of aldosterone producing adenoma (APA) has identified ATPase mutations in ATP1A1 and ATP2B3, which could lead to the opening of voltage-dependent calcium (Ca 2+ ) channels 7,8 . The CACNA1D mutation induced a shift in voltage-dependent gating to a more negative voltage, again implicating gain-of-function Ca 2+ channel mutations in APAs 9,10 . Therefore, aldosterone secretion is regulated