Genetic Dissection of Primary Aldosteronism in a Patient With MEN1 and Ipsilateral Adrenocortical Carcinoma and Adenoma

BACKGROUND

Adrenal tumors are found in up to 40% of patients with multiple endocrine neoplasia type 1 (MEN1). However, adrenocortical carcinomas (ACC) and primary aldosteronism (PA) are rare in MEN1.

CASE

A 48-year-old woman known to have primary hyperparathyroidism and hypertension with hypokalemia was referred for a right complex 8-cm adrenal mass with a 38.1 SUVmax uptake on 18F-FDG PET/CT. PA was confirmed by saline suppression test (aldosterone 1948 pmol/L-1675 pmol/L; normal range [N]: <165 post saline infusion) and suppressed renin levels (<5 ng/L; N: 5-20). Catecholamines, androgens, 24-hour urinary cortisol, and pituitary panel were normal. A right open adrenalectomy revealed a concomitant 4-cm oncocytic ACC and a 2.3-cm adrenocortical adenoma. Immunohistochemistry showed high expression of aldosterone synthase protein in the adenoma but not in the ACC, supporting excess aldosterone production by the adenoma.

GENETIC ANALYSIS

After genetic counseling, the patient underwent genetic analysis of leucocyte and tumoral DNA. Sequencing of MEN1 revealed a heterozygous germline pathogenic variant in MEN1 (c.1556delC, p.Pro519Leufs*40). The wild-type MEN1 allele was lost in the tumoral DNA of both the resected adenoma and carcinoma. Sequencing analysis of driver genes in PA revealed a somatic pathogenic variant in exon 2 of the KCNJ5 gene (c.451G>A, p.Gly151Arg) only in the aldosteronoma.

CONCLUSION

To our knowledge, we describe the first case of adrenal collision tumors in a patient carrying a germline pathogenic variant of the MEN1 gene associated with MEN1 loss of heterozygosity in both oncocytic ACC and adenoma and a somatic KCNJ5 pathogenic variant leading to aldosterone-producing adenoma. This case gives new insights on adrenal tumorigenesis in MEN1 patients.

ODP051 Presymptomatic Genetic Screening Leading to the Diagnosis of Paraganglioma Associated with Duodenal and Pancreatic Neuroendocrine Tumours in a Carrier of a Pathogenic MAX Variant

Introduction

MAXpathogenic variants have been found to predispose to pheochromocytomas and paragangliomas (PPGLs) and more recently to pituitary tumors 1.

Clinical Case

A 30 yo man presented to the emergency department for diplopia and high blood pressure (200/100mmHg). His workup showed elevated plasmatic normetanephrines (9. 01nmol/L; N <0.92) and a 3.7cm right adrenal mass with a density of 30HU. The patient underwent right laparoscopic adrenalectomy and the pathologist reported a 4.5cm pheochromocytoma with a PASS score of 4 and a Ki-67 of 2-4%. The patient was screened with a panel of 14 susceptibility genes for PPGLs (INVITAE, CA, USA) that revealed a pathogenic germline nonsense heterozygous MAX mutation (c.223C>Tp. Arg75*). This mutation was previously described in a family where four members suffered from bilateral PHEOs at a young age (28-35 yo) 2 . Following the identification of the pathogenic variant of MAX gene, the patient's father (61 yo) underwent genetic counselling and was found to carry the same germline mutation. His past medical history included long-standing hypertension with hypertensive cardiomyopathy and diabetes. His blood work showed a mildly elevated plasmatic normetanephrine (1.41nmol/L; N <1.2) with normal metanephrine. An abdominal CT-scan showed a 1.5cm precaval nodularity. On a complementary 18 F-FDG PET/CT, the precaval mass had a 3.5 SUVMax and a second mass was identified in the duodenum (D3) with an uptake of 4.9 SUVMax. The 68 GaDOTATE PET/CT confirmed the precaval (SUVMax36.3) and duodenal (SUVMax51.6) lesion and in addition, revealed a pancreatic mass (SUVMax9.3). The patient underwent a distal pancreatic, duodenal and precaval node resection. The pathology report showed a 1.7cm G1 pancreatic neuroendocrine tumor (NET) (Ki-67 <3%) and a 2.3cmG1 duodenal NET (Ki-67 <3%). The precaval node was a paraganglioma (PGL) with a preserved SDHB staining, negative cytokeratine 8/18 and a Ki-67 of 1.65%. The son had normal imaging of his pancreas. To our knowledge we report the second case of association of MAXmutation with gastrointestinal TNE.

Conclusion

This case presents the rare association of a familial MAX mutation presenting with a pheochromocytoma in the index case and a presymptomatic discovery of a PGL and multiple NETs in the father. This supports the hypothesis that MAXmutations might be associated with multiendocrinetumors 3. References: 1. Daly AF, Castermans E, et al. Pheochromocytomas and pituitary adenomas in three patients with MAX exon deletions. Endocr Relat Cancer. May 2018;25(5): L37-l42. doi: 10.1530/erc-18-00652. Comino-Méndez I, Gracia-Aznárez FJ, et al. Exome sequencing identifies MAX mutations as a cause of hereditary pheochromocytoma. Nat Genet. Jun 19 2011;43(7): 663-7. doi: 10.1038/ng.8613. Petignot S, Daly AF, et al. Pancreatic Neuroendocrine Neoplasm Associated with a Familial MAX Deletion. Horm Metab Res. Nov 2020;52(11): 784-787. doi: 10.1055/a-1186-0790

Presentation: No date and time listed

Loss of KDM1A in GIP-dependent primary bilateral macronodular adrenal hyperplasia with Cushing's syndrome: a multicentre, retrospective, cohort study

BACKGROUND

GIP-dependent primary bilateral macronodular adrenal hyperplasia with Cushing's syndrome is caused by aberrant expression of the GIP receptor in adrenal lesions. The bilateral nature of this disease suggests germline genetic predisposition. We aimed to identify the genetic driver event responsible for GIP-dependent primary bilateral macronodular adrenal hyperplasia with Cushing's syndrome.

METHODS

We conducted a multicentre, retrospective, cohort study at endocrine hospitals and university hospitals in France, Canada, Italy, Greece, Belgium, and the Netherlands. We collected blood and adrenal samples from patients who had undergone unilateral or bilateral adrenalectomy for GIP-dependent primary bilateral macronodular adrenal hyperplasia with Cushing's syndrome. Adrenal samples from patients with primary bilateral macronodular adrenal hyperplasia who had undergone an adrenalectomy for overt or mild Cushing's syndrome without evidence of food-dependent cortisol production and those with GIP-dependent unilateral adrenocortical adenomas were used as control groups. We performed whole genome, whole exome, and targeted next generation sequencing, and copy number analyses of blood and adrenal DNA from patients with familial or sporadic disease. We performed RNA sequencing on adrenal samples and functional analyses of the identified genetic defect in the human adrenocortical cell line H295R.

FINDINGS

17 patients with GIP-dependent primary bilateral macronodular adrenal hyperplasia with Cushing's syndrome were studied. The median age of patients was 43·3 (95% CI 38·8-47·8) years and most patients (15 [88%]) were women. We identified germline heterozygous pathogenic or most likely pathogenic variants in the KDM1A gene in all 17 patients. We also identified a recurrent deletion in the short p arm of chromosome 1 harboring the KDM1A locus in adrenal lesions of these patients. None of the 29 patients in the control groups had KDM1A germline or somatic alterations. Concomitant genetic inactivation of both KDM1A alleles resulted in loss of KDM1A expression in adrenal lesions. Global gene expression analysis showed GIP receptor upregulation with a log2 fold change of 7·99 (95% CI 7·34-8·66; p=4·4 × 10^-125), and differential regulation of several other G protein-coupled receptors in GIP-dependent primary bilateral macronodular hyperplasia samples compared with control samples. In vitro pharmacological inhibition and inactivation of KDM1A by CRISPR-Cas9 genome editing resulted in an increase of GIP receptor transcripts and protein in human adrenocortical H295R cells.

INTERPRETATION

We propose that GIP-dependent primary bilateral macronodular adrenal hyperplasia with Cushing's syndrome results from a two-hit inactivation of KDM1A, consistent with the tumour suppressor gene model of tumorigenesis. Genetic testing and counselling should be offered to these patients and their relatives.

FUNDING

Agence Nationale de la Recherche, Fondation du Grand défi Pierre Lavoie, and the French National Cancer Institute.

Small adrenal incidentaloma becoming an aggressive adrenocortical carcinoma in a patient carrying a germline APC variant

PURPOSE

Recent guidelines on adrenal incidentalomas suggested in patients with an indeterminate adrenal mass and no significant hormone excess that follow up with a repeat noncontrast CT or MRI after 6-12 months may be an option.

METHODS

We report the case of a 32-year-old woman who presented with a 2.9 × 1.9 cm left adrenal incidentaloma that was stable in size for 4 years. Ten years later the left adrenal mass was a stage IV adrenocortical carcinoma (ACC).

RESULTS

In 2006, a 32-year-old French Canadian woman was referred to endocrinology for a left 2.9 × 1.9 cm incidentally discovered adrenal mass (31 HU). She had normal hormonal investigation. The patient was followed with adrenal imaging and hormonal investigation yearly for 4 years and the lesion stayed stable in size over the 4 years. Ten years later, in 2016, the patient presented with renal colic. Urological CT unexpectedly revealed that the left adrenal mass was now measuring 9 × 8.2 cm and 2 new hepatic lesions were found. Biochemical workup demonstrated hypercorticism and hyperandrogenemia: plasma cortisol after 1 mg overnight DST of 476 nmol/L and DHEA-S of 14.0 μmol/L (N 0.9-6.5). Twenty-four hour urine steroid profiling was consistent with an adrenocortical carcinoma (ACC) co-secreting cortisol, androgens and glucocorticoid precursors. The diagnosis of ACC with hepatic ACC metastases was confirmed at histology. Following genetic analysis, germline heterozygous variant of uncertain significance (VUS) was identified in the exon 16 of the APC gene (c.2414G > A, p.Arg805Gln). Immunohistochemical staining's of the ACC was positive for IGF-2 and cytoplasmic/nuclear β-catenin staining.

CONCLUSIONS

This case illustrates that (1) small adrenal incidentaloma stable in size may evolve to ACC and (2) better genetic characterization of these patients may eventually give clues on this unusual evolution.

SUN-373 Small Adrenal Incidentaloma Stable in Size Becoming a Stage IV Adrenocortical Carcinoma 10 Years Later in a Young Patient Carrying a Germline APC Variant of Uncertain Significance (VUS)

Recent guidelines on adrenal incidentalomas suggested that patients with an indeterminate adrenal mass on imaging choosing not to undergo adrenalectomy to repeat imaging with either unenhanced computed tomography (CT) or Magnetic resonance imaging with chemical shift analysis in 6 to 12 months. If the adrenal mass is non-functioning and stable in size, patients may not require any additional monitoring.We report here a case of a young woman known for a small adrenal mass, stable in size for 4 years who was ultimately diagnosed with a Stage IV adrenal cortical carcinoma (ACC) 10 years later. Case report. In 2006, a 32-year-old French Canadian woman was referred in endocrinology for evaluation of a left 2.7 x 2.0 cm incidentally discovered adrenal mass. On presentation, her hormonal work up included a normal 1mg overnight dexamethasone suppression test (DST) and dehydroepiandrosterone sulfate (DHEA-S) within normal limits. On unenhanced computed tomography (CT), the radiodensity of the adrenal mass was 23 Hounsfield units (HU). The patient was followed with adrenal imaging and hormonal investigation yearly for 4 years and the adrenal mass demonstrated no growth in 4 years. Ten years after initial presentation, in 2016, after five years lost to follow up the patient presented with renal colic. Urological CT has unexpectedly revealed that the left adrenal mass had significantly progressed measuring 9 x 8.2 cm and 2 new hepatic lesions were identified. Biochemical work up demonstrated hypercortisolism and hyperandrogenemia: plasma cortisol after 1 mg overnight DST was 486 nmol/L and DHEA-S was 14.0 mmol/L (N 0.9-6.5). Twenty-four-hour urine steroid profiling was consistent with an ACC co-secreting cortisol, androgens and glucocorticoid precursors. The diagnosis of ACC with hepatic ACC metastases was confirmed by histology. Following genetic analysis, germline heterozygous variant of uncertain significance (VUS) was identified in the exon 16 of the APC gene NM_000038.5:c.2414G>A,(p.Arg805Gln) (rs200593940). The patient had no clinical manifestations of familial adenomatous polyposis. Immunohistochemical staining of the ACC were positive for IGF-2 and cytoplasmic/nuclear β-catenin, however, no somatic APC or beta-catenin mutations were found. This case illustrates that 1) small adrenal incidentaloma stable in size may progress to ACC 2) better genetic characterization of these patients may eventually give clues to this unusual evolution.

Genetic Characterization of GnRH/LH-Responsive Primary Aldosteronism

BACKGROUND

Recently, somatic β-catenin mutations (CTNNB1) identified in aldosterone-producing adenomas (APAs) from three women were suggested to be responsible for the aberrant overexpression of luteinizing hormone/choriogonadotropin receptor and gonadotropin-releasing hormone receptor in the APA.

OBJECTIVE

To genetically characterize patients with primary aldosteronism (PA) evaluated in vivo for gonadotropin-releasing hormone (GnRH)/luteinizing hormone (LH)-responsive aldosterone secretion.

METHOD

Patients with PA were evaluated in vivo to determine the possible regulation of aldosterone secretion by GnRH or LH. Genetic analysis of the CTNNB1, KCNJ5, ATP1A1, ATP2B3, CACNA1D, and GNAS genes were performed in this cohort and a control cohort of PA not tested in vivo for GnRH response.

RESULTS

We studied 50 patients with confirmed PA, including 36 APAs, 12 bilateral macronodular adrenal hyperplasias, 1 oncocytoma, and 1 bilateral hyperplasia with cosecretion of cortisol. Among 23 patients tested in vivo for GnRH response of aldosterone, 7 (30.4%) had a positive response, 4 (17.4%) a partial response, and 12 (52.2%) no response. No somatic CTNNB1 mutations were identified, but the disease-causing c.451G>C KCNJ5 mutation was found in two individuals with partial and no GnRH responses and an individual showing a positive response to LH. Two additional somatic pathogenic mutations, CACNA1D c.776T>A and ATP1A1 c.311T>G, were identified in two patients with no GnRH responses. In the 26 patients not tested for GnRH response, we identified 2 CTNNB1 (7.7%), 13 KCNJ5 (50%), and 1 CACNA1D (3.8%) mutations.

CONCLUSION

Aberrant regulation of aldosterone by GnRH is frequent in PA, but is not often associated with somatic CTNNB1, although it may be found with somatic KCNJ5 mutations.

CD36-deficient congenic strains show improved glucose tolerance and distinct shifts in metabolic and transcriptomic profiles

Deficiency of fatty acid translocase Cd36 has been shown to have a major role in the pathogenesis of metabolic syndrome in the spontaneously hypertensive rat (SHR). We have tested the hypothesis that the effects of Cd36 mutation on the features of metabolic syndrome are contextually dependent on genomic background. We have derived two new congenic strains by introgression of limited chromosome 4 regions of SHR origin, both including the defective Cd36 gene, into the genetic background of a highly inbred model of insulin resistance and dyslipidemia, polydactylous (PD) rat strain. We subjected standard diet-fed adult males of PD and the congenic PD.SHR4 strains to metabolic, morphometric and transcriptomic profiling. We observed significantly improved glucose tolerance and lower fasting insulin levels in PD.SHR4 congenics than in PD. One of the PD.SHR4 strains showed lower triglyceride concentrations across major lipoprotein fractions combined with higher levels of low-density lipoprotein cholesterol compared with the PD progenitor. The hepatic transcriptome assessment revealed a network of genes differentially expressed between PD and PD.SHR4 with significant enrichment by members of the circadian rhythmicity pathway (Arntl (Bmal1), Clock, Nfil3, Per2 and Per3). In summary, the introduction of the chromosome 4 region of SHR origin including defective Cd36 into the PD genetic background resulted in disconnected shifts of metabolic profile along with distinct changes in hepatic transcriptome. The synthesis of the current results with those obtained in other Cd36-deficient strains indicates that the eventual metabolic effect of a deleterious mutation such as that of SHR-derived Cd36 is not absolute, but rather a function of complex interactions between environmental and genomic background, upon which it operates.

Pharmacogenomics of metabolic effects of rosiglitazone

INTRODUCTION

Thiazolidinediones are increasingly used drugs for the treatment of Type 2 diabetes. The individual response to thiazolidinedione therapy, ranging from the variable degree of metabolic improvement to harmful side-effects, is empirical, yet the underlying mechanisms remain elusive. In order to assess the pharmacogenomic component of thiazolidinediones' metabolic action, we compared the effect of rosiglitazone in two genetically defined models of metabolic syndrome, polydactylous (PD) and BN.SHR4 inbred rat strains, with their insulin-sensitive, normolipidemic counterpart, the Brown Norway (BN) rat.

MATERIALS & METHODS

5-month-old male rats were fed a high-fat diet for 4 weeks, and the experimental groups received rosiglitazone (0.4 mg/100 g body weight) during the last 2 weeks of high-fat diet feeding. We assessed metabolic and morphometric profiles, oxidative stress parameters and gene expression in white adipose tissue.

RESULTS

In many followed parameters, we observed genetic background-specific effects of rosiglitazone administration. The mass and the sensitivity of visceral adipose tissue to insulin-stimulated lipogenesis increased with rosiglitazone treatment only in PD, correlating with a PD-specific significant increase in expression of prostaglandin D2 synthase. The glucose tolerance was enhanced in all strains, although fasting plasma glucose was increased by rosiglitazone in BN and BN.SHR4. Among the markers of lipid peroxidation, we observed the rosiglitazone-driven increase of plasma-conjugated dienes only in BN.SHR4. The genes with genotype-specific expression change included ADAM metallopeptidase domain 7, aquaporin 9, carnitine palmitoyltransferase 1B, caveolin 1, catechol-O-methyl transferase, leptin and prostaglandin D2 synthase 2.

CONCLUSION

Rosiglitazone's effects on lipid deposition and insulin sensitivity of peripheral tissues are largely dependent on the genetic background it acts upon.

Mapping of quantitative trait loci (QTL) of differential stress gene expression in rat recombinant inbred strains

OBJECTIVE

Stress has been shown to be a major environmental contributor to cardiovascular diseases through its effects on blood pressure variability and cardiac function. The cellular stress response is characterized by the expression of specific heat stress genes (hsps), under the transcriptional control of heat shock transcription factors (HSTFs). The levels of hsp mRNA depend on the severity of the stress, with hstf1 acting as a stress sensor. The aim of this work was to evaluate the genetic contribution of the variability in hsp expression, and to identify its putative quantitative trait loci (QTL).

METHODS

Twenty recombinant inbred rat strains (RIS) were studied. The animals underwent a standardized, identical 1 h immobilization stress in restraint cages, followed by 1 h of rest before sacrifice. Total RNA was extracted from the heart kidneys and adrenals, and the mRNA levels of hsp27, hsp70, hsp84, hsp86 and hsp105 were measured. The strain distribution pattern (SDP) of hsp expression was correlated with that of 475 polymorphic markers distributed throughout the RIS genome. A polymorphism of rat hstf1 in RIS was used for its mapping in RIS.

RESULTS

Despite an identical stress being applied to all strains, hsp expression showed up to a 1 2-fold gradient with little intra-strain variability, indicative of a strong genetic contribution to the trait Heritability ranged from 50 to 77% for most hsp genes in the three target organs. The continuous SDP of stress gene expression indicated the polygenic nature of the trait A common locus on chromosome 7 (at D7Cebrp187s3 marker) was consistently associated with all hsp expression in most of the organs [with a likelihood of odds (LOD) score of 3.0 for hsp27 expression]. We have mapped rat hstf1 on chromosome 7 at the same locus. Finally, the D4Mit19 marker was significantly associated with hsp84 expression in the heart (LOD score of 3.1).

CONCLUSION

Two loci were linked with the differential expression of HSPs in response to immobilization stress in target organs of RIS. The chromosome 7 locus unveiled for all HSPs could explain up to 42% of the observed inter-strain variability of hsp levels in response to stress. We propose hstf1 as a positional candidate at this locus.