Anti-NR3C1 monoclonal antibody, clone 850DU23.2.6

Recent advances in genetic analysis technologies such as next-generation sequencing (NGS) have considerably increased the incidental discovery of genetic abnormalities. Six heterozygous missense mutations of the human glucocorticoid receptor (GR; encoded by the NR3C1 gene) have been identified in the context of genetic screening of endocrine pathologies. GR, a nuclear receptor, hormone-induced transcription factor, is involved in many physiological processes. Nevertheless, the pathogenic significance of incidentally discovered mutations remains obscure. The aim of this work was to characterize these variants by evaluating their functional impact on GR signaling. Six original GR variants, located in exon 2, led to amino acid substitutions of the N-terminal domain of GR (F65V, M86V, A229T, A304E, N374S, and R386Q), excluding mainly the activation function tau core 1 domain, the potential site of functional interaction with transcriptional coregulators. Transient cotransfection in HEK293T cells of mutated GR-expressing vectors and a luciferase reporter established dose-response curves for dexamethasone. This excluded any major transactivation abnormality of the mutated GRs (ligand concentration leading to 50% maximal transactivation capacity approximate to 0.2 nM), with maximal transactivation capacity identical to that of the wild-type (WT) GR and without modification of the potentiation of transcriptional coactivator steroid receptor coactivator 2 except in N374S. Moreover, protein expression of mutated GRs and their cytonuclear translocation studied by immunocytochemistry were almost unchanged compared with WT GR. These results underline the silent nature of these missense GR variants and call for cautious interpretation of the discovery of genetic incidentalomas by NGS in the absence of detailed characterization in order to appropriately assess their functional impact on a particular signaling pathway. Copyright (C) 2019 Endocrine Society

Background: Glucocorticoid resistance syndrome (GRS) is caused by mutations of the glucocorticoid receptor (coded by the NR3C1 gene) and presents with signs of mineralocorticoid and/or androgen excess. Patient: A female patient presented at the age of almost 3 years with hypertensive and hypoglycemic seizure. She was diagnosed with GRS and was treated with antihypertensive medications and dexamethasone. She was later found to have MRI findings of punctuate microinfarcts at the basal ganglia, left thalamus and pons, possibly associated with uncontrolled hypertension. Increase of the dexamethasone dose up to 14 mg/day resulted in sufficient control of her symptoms. Results: Two mutations in the NR3C1 gene were identified: a novel mutation in exon 2 (p.E198X), and a previously described mutation in exon 8 (p.R714Q). Conclusion: GRS may present with life-threatening complications; this is the first report of hypertensive encephalopathy in association with GRS. Successful management of patients might require high doses of dexamethasone to control blood pressure.