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BACKGROUND: Recent clinical descriptions have shown that in adult patients, the cause of nondiabetic hypoglycemia (NDH) may be various genetically determined disorders of glucose metabolism or insulin synthesis/bioavailability. In this connection, in adult patients with NDH of unclear genesis, it is important to conduct a genetic study in order to search for mutations in genes associated with congenital disorders of glucose metabolism (CDGM).AIM: To evaluate the effectiveness of genetic testing to exclude CDGM in adult patients with idiopathic NDH.MATERIALS AND METHODS: Based on the analysis of the literature, a targeted panel has been developed, including 30 genes, mutations in which are associated with the following groups of diseases: 1) congenital hyperinsulinism (KCNJ11, ABCC8, GLUD1, HADH, UCP2, HNF4A, HNF1A, GCK, INSR, SLC16A1); 2) glycogen storage diseases (AGL); 3) other carbohydrate metabolism disorders (ALDOB, FBP1); 4) glycosylation defects (PMM2, ALG3, PGM1, MPI); 4) defects in fatty acid oxidation (ACADM, ETFA, ETFB, ETFDH, FLAD1, SLC25A32, SLC52A1, SLC52A2, SLC52A3); 5) disorders of ketone body metabolism (CPT1A, CPT2, HMGCL); 6) mitochondrial disorders (DLD). Twenty nine patients (n=29: with idiopathic NDH n=17 and with insulinoma n=12) aged 19 to 66 years underwent a genetic study using this custom panel.RESULTS: As a result of the examination 12 genetic variants (all heterozygous) were identified in 8 patients with idiopathic NDH (47%, 95% CI (23%; 72%)), at that two mutations were detected in three patients: in the genes AGL and HMGCL; ACADM and FLAD1, respectively; and one patient had three mutations: one mutation in the ETFA gene and two mutations in the ABCC8 gene. Frequencies of genetic variants: AGL — 18%, 95% CI (4%; 43%), ETFA — 12% (1%; 36%), HMGCL — 6% (0%; 29%), ALDOB — 6% (0%; 29%), CPT1A — 6% (0%; 29%), ABCC8 — 6% (0%; 29%), ACADM — 6% (0%; 29%), FLAD1 — 6% (0%; 29%). 5 genetic variants (all heterozygous) were identified in 5 patients with insulinoma (42%, 95% ДИ (15%; 72%)). Frequencies of genetic variants: ABCC8 — 17%, 95% CI (2%; 48%), HNF1A — 8% (0%; 38%), ETFDH — 8% (0%; 38%), MPI — 8% (0%; 38%). We did not include benign variants in this analysis. At the same time, clinically significant variants were identified only in one patient from the group with idiopathic NDH (6%, 95% CI (0%; 29%)) in the ABCC8 gene and in one patient from the group with insulinoma (8%, 95% CI (0%; 38%)) in the same gene congenital hyperinsulinism (CHI).CONCLUSION: A panel of 30 genes has been developed, variants of which are associated with a CDGM. The results of our study confirm the possibility of detecting CDGM in adulthood, in particular CHI, and indicate the need for genetic testing, primarily in patients with idiopathic NDH.

BACKGROUND: It is known that insulinoma in approximately 5% of cases is associated with multiple endocrine neoplasia type 1 syndrome (MEN1), in which the prognosis and management tactics of patients have been developed in detail. The diagnosis of MEN1 often does not require genetic confirmation, since the syndrome has a typical clinical picture. At the same time, a combination of this tumor with other hereditary syndromes is found in the literature, which are characterized by the presence of malignant neoplasms of various localizations, primary multiple lesions, hormonal and other disorders. Thus, it is relevant to search for the genetic causes that cause the development of insulinoma, in addition to MEN1.AIM: to evaluate the frequency of detection of genetic causes of the development of insulin-producing tumors of the pancreas, in addition to MEN1; to analyze the phenotypic characteristics of patients with such tumors.MATERIALS AND METHODS: Based on the analysis of literature for the period up to 2020, a panel has been developed that includes coding regions of 10 genes (MEN1, VHL, TSC1, TSC2, KRAS, YY1, CDKN2A, MLH1, ADCY1, CACNA2D2) involved in the development of insulinoma. In 32 patients diagnosed with insulinoma, verified by pathomorphological examination, with the absence of clinical and/or genetic data indicating MEN1 syndrome, a panel of genes was sequenced with subsequent analysis of the identified genetic variants and phenotypic data obtained from the medical records of patients. In one patient, an additional molecular genetic study of the «Endom» panel was performed, revealing genetic variants of coding regions of 377 genes associated with endocrine diseases.RESULTS: In 8 patients (25%, 95% CI (11%; 43%)), 9 variants of mutations were identified that were not classified as benign, at that two mutations in the TSC2 gene were detected in one patient. Frequencies of genetic variants: TSC2 — 13%, 95% CI (4%; 29%), MEN1 — 6% (1%; 21%), MLH1 — 3% (0%;16%), CDKN2A/P16INK4A — 3% (0%;16%). When comparing patients with the identified mutation, with the exception of benign (n=8), and patients without mutation or with a benign mutation (n=24), there were no differences in the Grade (degree of differentiation), Ki67 proliferation index, frequency of concomitant tumors, burdened history, multiple pancreatic lesions or recurrence of insulinoma, however, patients with germinal mutation were found at the level of statistical trend to be younger at the manifestation of insulinoma and to have bigger tumors. In a patient who underwent an additional molecular genetic study using the new «Endome» panel, previously undescribed gene variants (APC and KIF1B) associated with various sporadic tumors, including endocrine ones, were identified.CONCLUSION: A panel of 10 genes has been developed, mutations of which are associated with insulinoma. A relatively high incidence of genetically determined insulinoma was determined (25% of cases), in half of cases — against the background of tuberous sclerosis. We consider it relevant to evaluate the effectiveness of genetic testing for patients with insulinoma. We believe that, first of all, patients with a high risk of hereditary pathology should be examined: with the manifestation of the disease at a young age and with a large tumor. The identification of a genetic mutation will make it possible to determine the prognosis of the disease, optimize the monitoring algorithm in order to timely identify concomitant diseases-components of the hereditary syndrome, and conduct genetic counseling of the family.

BACKGROUND: Insulinoma is a pancreatic neuroendocrine tumor that manifests by impaired carbohydrate metabolism with the development of hypoglycemic syndrome. The instrumental methods used at the present stage do not always make it possible to identify a tumor; moreover, the data obtained often contradict each other. Thus, the search for new possibilities of visualization of insulinoma is relevant.AIM: Evaluation of diagnostic effectiveness of scintigraphy with single-photon emission computed tomography combined with X-ray computed tomography (SPECT/CT) with 99mTc-Tectrotide for insulinoma in a Russian cohort of patients.MATERIALS AND METHODS: A single-centre (Endocrinology Research Centre of the Ministry of Health of the Russia), experimental, single-stage, controlled study. In the years 2017–2021 patients with pancreatic insulinoma (group 1) and hyperinsulinemic hypoglycemia of a different genesis (group 2) with negative or contradictory results of the 1st line imaging methods (ultrasound, magnetic resonance imaging (MRI), computed tomography (CT)) were included. All participants underwent the whole-body scintigraphy and low-dose SPECT/CT with 99mTc-Tectrotide (500–900 MBq). The studies were performed on a tomograph of the SPECT/GE Discovery NM/CT 670 using low-energy high-resolution collimators (LEHR) in the «whole body» mode.RESULTS: In the group 1 (n=21), according to the results of a pathomorphological study, the presence of 26 insulin-producing tumors was confirmed. Group 2 included 9 patients. According to the SPECT/CT with 99mTc-Tectrotide, 14 tumors were diagnosed in group 1 out of 26 insulin-producing tumors of the pancreas, and negative results were obtained in group 2 in 100% of cases. Thus, the sensitivity and specificity of the method were: 54%, 95% CI [33%; 73%] and 100%, 95% CI [68%; 100%], respectively.CONCLUSION: SPECT/CT with 99mTc-Tectrotide can detect insulinoma in 54% of cases with negative or contradictory results of 1st-line imaging methods (ultrasound, MRI, CT). This study can be effectively used as an alternative to SPECT/CT with 111In-octreotide, as a 2nd-line method for topical search for an insulin-producing pancreatic tumor.

Background: The diagnostic threshold of β-hydroxybutyrate (BHB) at the moment of hypoglycemia in insulinoma was developed for venous blood many years ago, when there were no alternative ways to measure ketones. Number of works, mainly on patients with diabetes mellitus, found differences in the measurement of this indicator in venous and capillary blood, but the results were contradictory. Moreover, this study was not previously used in the diagnosis of non-diabetic hypoglycemia (NDH) in adults on the territory of the Russian Federation.Aim: To estimate the effectiveness of the method for determining BHB in capillary blood and its place in the diagnosis of NDH.Materials and methods: We conducted an experimental, cross-sectional, comparative study and included patients with suspected NDH who underwent a standard fast test. The BHB level in capillary blood was determined every 6 hours during the fast test and at its completion.Results: Based on the results of the fast test, the participants (n=154) were divided into groups: with hyperinsulinemic variant of NDH and IFRoma (n=98; group 1), with hypoinsulinemic variant of NDH /absence of NDH (n=56; group 2). When comparing the level of BHB at the moment of fasting completion, significant differences were obtained between groups 1 and 2 (p

Adrenal insufficiency (AI) is a syndrome caused by disturbance in the synthesis and secretion of hormones of the adrenal cortex, which ensure the vital activity, energy and water-salt homeostasis. The widest hormonal deficiency is observed in primary hypocorticism, when the synthesis of not only glucocorticoids (GC) and adrenal androgens, but also mineralocorticoids is disrupted. Lifelong replacement therapy with GCs for this pathology may be associated with a risk of bone loss and osteoporosis. However, at present, there are no clear guidelines for diagnosis of bone condition, including and bone mineral density (BMD) monitoring during treatment with GCs in patients with AI. This review summarizes collected data on the key pathogenetic links of glucocorticoid-induced osteoporosis, incidence of decreased BMD and fractures in patients with AI. In this review factors that influence bone metabolism in this cohort of patients are considered: the type and the dose of prescribed GCs, the type (primary, secondary, HH in congenital adrenal cortex dysfunction) and the duration of AI, age, gender, and the presence of concomitant endocrine disorders (hypogonadism, growth hormone (GH) deficiency). In addition, the review presents data on the effect of adrenal androgen replacement therapy and recombinant GH therapy on bone metabolism in secondary AI.