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Context: Germline CDKN1B variants predispose patients to multiple endocrine neoplasia type 4 (MEN4), a rare MEN1-like syndrome, with <100 reported cases since its discovery in 2006. Although CDKN1B mutations are frequently suggested to explain cases of genetically negative MEN1, the prevalence and phenotype of MEN4 patients is poorly known, and genetic counseling is unclear., Objective: To evaluate the prevalence of MEN4 in MEN1-suspected patients and characterize the phenotype of MEN4 patients., Design: Retrospective observational nationwide study. Narrative review of literature and variant class reassessment., Patients: We included all adult patients with class 3/4/5 CDKN1B variants identified by the laboratories from the French Oncogenetic Network on Neuroendocrine Tumors network between 2015 and 2022 through germline genetic testing for MEN1 suspicion. After class reassessment, we compared the phenotype of symptomatic patients with class 4/5 CDKN1B variants (ie, with genetically confirmed MEN4 diagnosis) in our series and in literature with 66 matched MEN1 patients from the UMD-MEN1 database., Results: From 5600 MEN1-suspected patients analyzed, 4 with class 4/5 CDKN1B variant were found (0.07%). They presented with multiple duodenal NET, primary hyperparathyroidism (PHPT) and adrenal nodule, isolated PHPT, PHPT, and pancreatic neuroendocrine tumor. We listed 29 patients with CDKN1B class 4/5 variants from the literature. Compared with matched MEN1 patients, MEN4 patients presented lower NET incidence and older age at PHPT diagnosis., Conclusion: The prevalence of MEN4 is low. PHPT and pituitary adenoma represent the main associated lesions, NETs are rare. Our results suggest a milder and later phenotype than in MEN1. Our observations will help to improve genetic counseling and management of MEN4 families., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Endocrine Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Context: Oral once-daily dual-release hydrocortisone (DR-HC) replacement therapy has demonstrated an improved metabolic profile compared to conventional 3-times-daily (TID-HC) therapy among patients with primary adrenal insufficiency. This effect might be related to a more physiological cortisol profile, but also to a modified pattern of cortisol metabolism., Objective: This work aimed to study cortisol metabolism during DR-HC and TID-HC., Design: A randomized, 12-week, crossover study was conducted., Intervention and Participants: DC-HC and same daily dose of TID-HC were administered to patients with primary adrenal insufficiency (n = 50) vs healthy individuals (n = 124) as controls., Main Outcome Measures: Urinary corticosteroid metabolites were measured by gas chromatography/mass spectrometry at 24-hour urinary collections., Results: Total cortisol metabolites decreased during DR-HC compared to TID-HC (P < .001) and reached control values (P = .089). During DR-HC, 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) activity measured by tetrahydrocortisol + 5α-tetrahydrocortisol/tetrahydrocortisone ratio was reduced compared to TID-HC (P < .05), but remained increased vs controls (P < .001). 11β-HSD2 activity measured by urinary free cortisone/free cortisol ratio was decreased with TID-HC vs controls (P < .01) but normalized with DR-HC (P = .358). 5α- and 5β-reduced metabolites were decreased with DR-HC compared to TID-HC. Tetrahydrocortisol/5α-tetrahydrocortisol ratio was increased during both treatments, suggesting increased 5β-reductase activity., Conclusions: The urinary cortisol metabolome shows striking abnormalities in patients receiving conventional TID-HC replacement therapy, with increased 11β-HSD1 activity that may account for the unfavorable metabolic phenotype in primary adrenal insufficiency. Its change toward normalization with DR-HC may mediate beneficial metabolic effects. The urinary cortisol metabolome may serve as a tool to assess optimal cortisol replacement therapy., (© The Author(s) 2020. Published by Oxford University Press on behalf of the Endocrine Society.)

Introduction: Carney Complex (CNC) is a rare multiple endocrine and nonendocrine neoplasia syndrome. Manifestations and genotype-phenotype correlations have been described by retrospective studies, but no prospective study evaluating the occurrence of the different manifestations has been available so far., Methods: This multicenter national prospective study included patients with CNC, primary pigmented nodular adrenal disease (PPNAD), or a pathogenic PRKAR1A mutation; after a full initial workup, participants were followed for 3 years with annual standardized evaluation., Results: The cohort included 70 patients (50 female/20 male, mean age 35.4 ± 16.7 years, 81% carrying PRKAR1A mutation). The initial investigations allowed identification of several manifestations. At the end of the 3-year follow-up, the newly diagnosed manifestations of the disease were subclinical acromegaly in 6 patients, bilateral testicular calcifications in 1 patient, and cardiac myxomas in 2 patients. Recurrences of cardiac myxomas were diagnosed in 4 patients during the 3-year follow-up study period. Asymptomatic abnormalities of the corticotroph and somatotroph axis that did not meet criteria of PPNAD and acromegaly were observed in 11.4% and 30% of the patients, respectively. Patients carrying the PRKAR1A c.709-7del6 mutation had a mild phenotype., Conclusion: This study underlines the importance of a systematic follow-up of the CNC manifestations, especially a biannual screening for cardiac myxoma. By contrast, regular screening for the other manifestations after a first extensive workup could be spread out, leading to a lighter and more acceptable follow-up schedule for patients. These are important results for recommendations for long-term management of CNC patients., (© Endocrine Society 2020. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Context: RTHα is a recently discovered resistance to thyroid hormone (RTH) due to mutation of THRA, the gene encoding TRα1, the thyroid hormone receptor. It has been described in a few patients with growth retardation, short stature, and a low free T4/free T3 (FT4/FT3) ratio., Objective: A 27-year-old patient presenting with dwarfism and a low FT4/FT3 ratio was investigated., Design: Clinical, biochemical, and radiological data were collected. Whole exome sequencing was performed in the patient and her relatives., Results: The patient exhibited congenital macrocytic anemia and severe bone malformation with growth retardation, dwarfism, clavicular agenesis, and abnormalities of the fingers, toes, and elbow joints. In adulthood, she presented with active behavior, chronic motor diarrhea, and hypercalcemia. Treatment with T3 led to heart rate acceleration, worsening of diarrhea, and TSH suppression. Low resting energy expenditure normalized on T3. rT3, SHBG, and IGF-1 remained normal. A de novo monoallelic missense mutation in THRA was discovered, the N359Y amino acid substitution (c.1075A>T), which affected both the TRα1 and the non-receptor isoform TRα2. The mutant TRα1 had a decrease in transcriptional activity related to decreased T3 binding and a dominant-negative effect on the wild-type receptor., Conclusions: This patient presents a new phenotype including more significant bone abnormalities, lower TSH, and higher FT3 levels, without certainty of all her symptoms with the TRα1(N359Y) mutation. This case suggests that patients with a low FT4/FT3 ratio should be screened for THRA mutations, even if clinical and biological features differ from previous reported cases of RTHα.

Context: Primary bilateral macronodular adrenal hyperplasia (PBMAH) is a rare cause of primary adrenal Cushing's syndrome (CS). ARMC5 germline mutations have been identified recently in PBMAH., Objective: To determine the prevalence of ARMC5 mutations and analyze genotype-phenotype correlation in a large cohort of unrelated PBMAH patients with subclinical or clinical CS., Patients and Methods: ARMC5 was sequenced in 98 unrelated PBMAH index cases. PBMAH was identified by bilateral adrenal nodular enlargement on computed tomography scan. The effect on apoptosis of ARMC5 missense mutants was tested in H295R and HeLa cells. Clinical and hormonal data were collected including midnight and urinary free cortisol levels, ACTH, androgens, renin/aldosterone ratio, cortisol after overnight dexamethasone suppression test, cortisol and 17-hydroxyprogesterone after ACTH 1-24 stimulation and illegitimate receptor responses. Computed tomography and histological reports were analyzed., Results: ARMC5-damaging mutations were identified in 24 patients (26%). The missense mutants and the p.F700del deletion were unable to induce apoptosis in both H295R and HeLa cell lines, unlike the wild-type gene. ARMC5-mutated patients showed an overt CS more frequently, compared to wild-type patients: lower ACTH, higher midnight plasma cortisol, urinary free cortisol, and cortisol after dexamethasone suppression test (P = .003, .019, .006, and <.001, respectively). Adrenals of patients with mutations were bigger and had a higher number of nodules (P = .001 and <.001, respectively)., Conclusions: ARMC5 germline mutations are common in PBMAH. Index cases of mutation carriers show a more severe hypercortisolism and larger adrenals. ARMC5 genotyping may help to identify clinical forms of PBMAH better and may also allow earlier diagnosis of this disease.

Context: Primary aldosteronism is one of the leading causes of secondary hypertension, causing significant morbidity and mortality. A number of genetic defects have recently been identified in primary aldosteronism, whereas we identified mutations in ARMC5, a tumor-suppressor gene, in cortisol-producing primary macronodular adrenal hyperplasia., Objective: We investigated a cohort of 56 patients who were referred to the National Institutes of Health for evaluation of primary aldosteronism for ARMC5 defects., Methods: Patients underwent step-wise diagnosis, with measurement of serum aldosterone and plasma renin activity followed by imaging, saline suppression and/or oral salt loading tests, plus adrenal venous sampling. Cortisol secretion was also evaluated; unilateral or bilateral adrenalectomy was performed, if indicated. DNA, protein, and transfection studies in H295R cells were conducted by standard methods., Results: We identified 12 germline ARMC5 genetic alterations in 20 unrelated and two related individuals in our cohort (39.3%). ARMC5 sequence changes in 6 patients (10.7%) were predicted to be damaging by in silico analysis. All affected patients carrying a variant predicted to be damaging were African Americans (P = .0023)., Conclusions: Germline ARMC5 variants may be associated with primary aldosteronism. Additional cohorts of patients with primary aldosteronism and metabolic syndrome, particularly African Americans, should be screened for ARMC5 sequence variants because these may underlie part of the known increased predisposition of African Americans to low renin hypertension.

Context: Inactivating germline mutations of the probable tumor suppressor gene, armadillo repeat containing 5 (ARMC5), have recently been identified as a genetic cause of macronodular adrenal hyperplasia (MAH)., Objective: We searched for ARMC5 mutations in a large cohort of patients with MAH. The clinical phenotype of patients with and without ARMC5 mutations was compared., Methods: Blood DNA from 34 MAH patients was genotyped using Sanger sequencing. Diurnal serum cortisol measurements, plasma ACTH levels, urinary steroids, 6-day Liddle's test, adrenal computed tomography, and weight of adrenal glands at adrenalectomy were assessed., Results: Germline ARMC5 mutations were found in 15 of 34 patients (44.1%). In silico analysis of the mutations indicated that seven (20.6%) predicted major implications for gene function. Late-night cortisol levels were higher in patients with ARMC5-damaging mutations compared with those without and/or with nonpathogenic mutations (14.5 ± 5.6 vs 6.7 ± 4.3, P < .001). All patients carrying a pathogenic ARMC5 mutation had clinical Cushing's syndrome (seven of seven, 100%) compared with 14 of 27 (52%) of those without or with mutations that were predicted to be benign (P = .029). Repeated-measures analysis showed overall higher urinary 17-hydroxycorticosteroids and free cortisol values in the patients with ARMC5-damaging mutations during the 6-day Liddle's test (P = .0002)., Conclusions: ARMC5 mutations are implicated in clinically severe Cushing's syndrome associated with MAH. Knowledge of a patient's ARMC5 status has important clinical implications for the diagnosis of Cushing's syndrome and genetic counseling of patients and their families.