Analysis of BCLI, N363S and ER22/23EK Polymorphisms of the Glucocorticoid Receptor Gene in Adrenal Incidentalomas

CONTEXT: Patients with adrenal incidentalomas (AI) may experience detrimental consequences due to a minimal cortisol excess sustained by adrenal adenoma. SNPs of the glucocorticoid receptor gene (NR3C1) modulate individual sensitivity to glucocorticoids and may interfere with the clinical presentation. OBJECTIVE: To compare the frequency of N363S, ER22/23EK and BclI SNPs in patients with AI with the general population and to evaluate whether these SNPs are linked to consequences of cortisol excess. SETTING: Multicentric, retrospective analysis of patients referred from 2010 to 2014 to 4 centers (Orbassano, Milano, Messina [Italy] and Zagreb [Croatia]). PATIENTS: 411 patients with AI; 153 males and 258 females and 186 from blood donors. MAIN OUTCOMES MEASURES: All patients and controls were genotyped for BclI, N363S and ER22/23EK and SNPs frequency was associated with clinical and hormonal features. RESULTS: SNP frequency was: SNP frequency was: N363S 5.4% (MAF 0.027), BclI 54.7% (MAF 0.328), ER22/23EK 4.4% (MAF 0.022), without any significant difference between patients and controls. N363S was more frequent in hypertensive patients (p = 0.03) and was associated with hypertension (p = 0.015) in patients with suppressed cortisol after the 1-mg DST. CONCLUSIONS: Our results demonstrate that SNPs of the glucocorticoid receptor gene do not play a pathogenetic role for AI. The impact of any single SNP on the phenotypic expression of minimal cortisol excess is limited and their analysis does not provide additional data that may be exploited for patient management.