We now show that almost all known PA-associated CLCN2 mutations markedly increase ClC-2 chloride currents and generate knock-in mice expressing a constitutively open ClC-2 Cl<sup>-</sup> channel as mouse model for PA.
Germline CLCN2 mutations appear to account for a substantial proportion of early-onset primary aldosteronism cases, and genetic testing for mutations in this gene should be considered in appropriate cases.
Eight probands had novel heterozygous variants in CLCN2, including two de novo mutations and four independent occurrences of a mutation encoding an identical p.Arg172Gln substitution; all relatives with early-onset primary aldosteronism carried the CLCN2 variant found in the proband.
However, the adrenal cortex of all IHA adrenals harbored at least 1 CYP11B2-positive aldosterone-producing cell cluster (APCC) or micro-aldosterone-producing adenomas.
We implemented immunohistochemistry for aldosterone synthase (CYP11B2) and 17α-hydroxylase/17,20 lyase (CYP17A1) in adrenal glands resected from patients without improvement of PA after surgical treatment and from those with limitations in AVS interpretation.
The development of antibodies against the terminal enzyme of aldosterone biosynthesis (CYP11B2) has permitted the further characterization of normal adrenals and resected adrenals from patients with primary aldosteronism.
Adrenal tumors in patients with PA can demonstrate clear heterogeneity in CYP11B2 expression and somatic mutations in driver genes for aldosterone production.
FH-1 (glucocorticoid-remediable hyperaldosteronism) results from a chimeric gene (5'-end of CYP11B1 fused to 3'-end of CYP11B2) and accounts for ∼1% of PA. FH-3 is very rare, is caused by bilateral expression of mutant KCNJ5 and usually results in florid hyperaldosteronism requiring early bilateral adrenalectomy.
The objective of the study was to investigate the significance of immunohistochemical staining to detect CYP11B2 and CYP11B1 in adrenal tissue of patients with PA.
Here we selected two commonly studied CYP11B2 alleles: T-344C, A2718G to explore their associations with PA risk by meta-analyses of published case-control studies.
The present study aimed to investigate the expression of aldosterone synthase (CYP11B2), adrenocorticotropic hormone receptor (ACTH-R) and their regulating transcription factors in adrenal incidentalomas (AIs) from normotensive and hypertensive patients to distinguish subclinical or atypical primary aldosteronism (PA) from AIs.
Histopathological analysis of the resected adrenal tumors from 5 PA/SCS patients revealed a single adenoma in 3, and double adenomas in 2, with varying degrees of positive immunoreactivities for steroidgenic enzymes (3β-HSD, P450(C17)) by immunohistochemical study as well as CYP11B2 mRNA expression as measured by real-time RT-PCR.
The levels of CYP11B2 and CYP17 mRNA were significantly increased in the adjacent tissues of microadenomas, as compared with macroadenomas or NF (p<0.05), whereas no significant differences in the CYP21 and HSD3B2 mRNA levels were found between the PA sub-groups.
Familial hyperaldosteronism type II (FH-II) is characterized by the familial occurrence of primary aldosteronism; unlike FH-I, it is not glucocorticoid-remediable and not associated with the hybrid CYP11B1/CYP11B2 gene mutation.
Familial hyperaldosteronism type II (FH-II) is characterized by inheritance of primary aldosteronism (PAL) but, unlike FH-I, is not glucocorticoid remediable and not associated with the hybrid CYP11B1/CYP11B2 gene mutation.
Postoperative differentiation between unilateral adrenal adenoma and bilateral adrenal hyperplasia in primary aldosteronism by mRNA expression of the gene CYP11B2.
The aim of our study was to identify genetic variants that influence the phenotype of patients with PA. We hypothesized that genetic variants potentially affecting aldosterone production (aldosterone synthase, CYP11B2), renal proximal tubule reabsorption (alpha-adducin), or the mechanisms of counterbalance leading to vasodilatation and sodium excretion (bradykinin B(2)-receptor, B(2)R) could influence the clinical and biochemical characteristics of patients with PA. We studied three polymorphisms of these genes (C-344T of CYP11B2, G460W of alpha-adducin, and C-58T of B(2)R) in 167 primary aldosteronism patients (56 with aldosterone-producing adenoma and 111 with idiopathic hyperaldosteronism).