BACKGROUND: Loss-of-function mutations in the TSH receptor gene (TSHR) (NP_000360.2) are the potential causes of thyroid dysgenesis in patients with congenital hypothyroidism. Heterozygous variants of the TSHR gene lead to partial resistance to TSH, homozygous and compound heterozygous variants have been shown to cause CH due to thyroid hypoplasia or TSH resistance. Recently more and more articles in this field have appeared in the international literature sources, while local publications are limited. The studies are necessary to understand the etiology, pathogenesis of the disease, to improve the management of these patients.AIM: To assess the frequency of incidence of pathogenic variants of the TSHR gene in children with CH due to thyroid dysgenesis. To study inheritance and phenotypic patterns of CH in families.MATERIALS AND METHODS: In this single-center interventional one-stage non-comparative study a group of CH patients was examined. The patients underwent neck ultrasound and radionuclide imaging. The examination was performed 14 days after hormone replacement therapy suspension or prior to its initiation. The structure of thyroid dysgenesis was estimated, genetic testing for mutations in the TSHR gene was performed using the NGS method.RESULTS: The study included 95 children with primary CH (75 girls; 20 boys). The patients’ median age at the time of examination was 6.2 years [4.5; 8.9], the median level of neonatal TSH was 157.5 mU/l [60.9; 257.2]. Ectopic thyroid was found in 52% of children, aplasia in 36%, hypoplasia and hemiagenesis in 10% and 2%, respectively. In 5.4% of cases (in 5 out of 95 patients), different variants of the TSH gene were detected. Two children had heterozygous p.R450H and p.D487N variants in TSHR gene, two patients was homozygous for the p.S49Afs * 9 variant, one child had compound heterozygous variants (p.A485D and p.R450H). According to ultrasound imaging, all patients had thyroid hypoplasia of varying severity. Three children underwent thyroid scintigraphy, which revealed decreased 99mТc pertechnetate uptake (0.3–0.9%).CONCLUSION: In our study, the incidence of different variants in the TSHR gene in children with CH was 5.3%. Our analysis uncovered two previously undescribed variants. Genetic testing may be able to help with making the diagnosis, patient’s management, and genetic counseling.

BACKGROUND: The frequency of ectopia of thyroid gland among all types of dysgenesis varies from 30 to 70%, its most common localization is the root of the tongue. Otorhinolaryngologists, oncologists, pediatricians can take lingual ectopia for hypertrophy of the lingual tonsil or fibroma of the tongue root, which leads to unreasonable surgical treatment. Thyroid scintigraphy plays a key role in the diagnosis of ectopia.AIM: To assess the etiological structure of congenital hypothyroidism (CH) and demonstrate the clinical course in patients with ectopic thyroid tissue in the root of the tongue.MATERIALS AND METHODS: A group of patients with CH was examined. All patients underwent neck ultrasound and radionuclide imaging. The examination was carried out against the background of the abolition of hormone replacement therapy for 14 days or before its initiation. Patients with ectopia in the root of the tongue underwent videofibrolaryngoscopy. Some patients underwent a genetic study with using genes panel of a panel of candidate genes responsible for the development of CH using the NGS method. The molecular genetic study was conducted to some patients, next-generation sequencing with the genes panel.RESULTS: The study included 73 patients with primary CH aged from 2 weeks to 17.3 years: 69 children were diagnosed based on the results of neonatal screening, 4 children with thyroid ectopia were first examined older than 6 years. The median age of patients at the time of the examination was 6.9 years [4.8; 10.0]. By data of ultrasound aplasia was diagnosed in 47.9% of patients, one child had hemiagenesis and ectopic thyroid tissue of various localization was detected in 26.0% of children. In 24.7% of children thyroid tissue was found in a typical location. Scintigraphy confirmed thyroid aplasia in 65.7% of children. Examination revealed various variants of ectopically located thyroid tissue in 31 children (42.4%): thyroid ectopia in the root of the tongue in 25 children (80.6%), ectopia in the sublingual region in 5 children (16.2%), double ectopia was detected in 1 child. The median level of TSH in newborns with ectopic thyroid gland was 124 IU/ml and was significantly lower than in children with aplasia — 219 IU/ml, p<0.05. On the other side the level of TG in children with ectopia was significantly higher than in children with aplasia — 37.12 ng/ml versus 0.82 ng/ml, p><0.05. CONCLUSION: Combination of two methods is the best diagnostic approach to determine the etiology of CH — ultrasound and scintigraphy studies compensates deficiencies of each other. Our study demonstrates the importance of scintigraphy in children with CH and patients with the formation of the root of the tongue and the anterior surface of the neck in order to avoid unnecessary removal of the thyroid gland. In case of confirmation of thyroid ectopia in the root of the tongue and in the absence of symptoms of obstruction or bleeding, it is recommended to refer the patient to an endocrinologist for conservative treatment. ><0.05. On the other side the level of TG in children with ectopia was significantly higher than in children with aplasia — 37.12 ng/ml versus 0.82 ng/ml, p< 0.05.CONCLUSION: Combination of two methods is the best diagnostic approach to determine the etiology of CH — ultrasound and scintigraphy studies compensates deficiencies of each other. Our study demonstrates the importance of scintigraphy in children with CH and patients with the formation of the root of the tongue and the anterior surface of the neck in order to avoid unnecessary removal of the thyroid gland. In case of confirmation of thyroid ectopia in the root of the tongue and in the absence of symptoms of obstruction or bleeding, it is recommended to refer the patient to an endocrinologist for conservative treatment.

Mutations in the GLIS3 gene encoding the GLIS3 transcription factor are cause of a rare syndromic form of neonatal diabetes mellitus (NDM) with congenital hypothyroidism. Additional features include congenital glaucoma, hepatic fibrosis, polycystic kidneys, developmental delay and other anomalies. This disease in foreign literature is called NDH-syndrome (Neonatal diabetes and Hypothyroidism syndrome).We present the description of a patient with this syndrome with novel homozygous GLIS3 mutation.Our patient is a female, who was born with a weight of 1680 gr, length of 44 cm to consanguineous parents. She developed diabetes on 2 day after birth, requiring continuous intravenous insulin. On day 5 of life hypothyroidism was identified. ­Thyroid anatomy was normal on ultrasound scan. NDH syndrome was suspected.Genetic analysis revealed a novel homozygous mutation c.1836delT, p.Ser612ArgfsTer33 in exon 5 in GLIS3 gene.To date, the patient is followed up for 4 years in total. Currently, growth retardation, psychomotor and speech development persist. Carbohydrate metabolism and thyroid profile has been subcompensated against the background of replacement therapy. No other components of the syndrome have been identified.In this report, we have demonstrated the features of the neonatal diabetes mellitus in a patient with a defect in the GLIS3 gene. Early genetic verification of the diagnosis contributes to the timely starting of personalized therapy, can improve the quality of life of such patients, and, given the nature of inheritance, is necessary for medical genetic counseling of the family.

Congenital hypothyroidism is an important issue of pediatric endocrinology at which timely diagnosis and treatment can prevent the development of severe cases of the disease. The developed clinical guidelines are a working tool for a practicing physician. The target audience is pediatric endocrinologists and pediatricians. They briefly and logically set out the main definition of the disease, epidemiology, classification, methods of diagnosis and treatment, based on the principles of -evidence-based medicine.

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Background: Currently more than 50 mutations of the INS gene are known to affect the various stages of insulin biosynthesis in the beta cells of the pancreas. However only individual cases of diabetes mellitus (DM) associated with heterozygous mutations in the coding region of the INS gene were reported in Russian Federation. We report a group of patients with a clinical manifestation of DM caused by mutations in both coding and non-coding regions of the INS gene. The patients with a mutation in the intron of the INS gene are reported for the first time in Russian Federation Materials and methods : 60 patients with an isolated course of neonatal DM (NDM), 52 patients with a manifestation of DM at the age of 7–12 months and the absence of the main autoimmune markers of type 1 DM, 650 patients with the MODY phenotype were included in the study. NGS technology was used for molecular genetic research. Author’s panel of primers (Custom DNA Panel) was used for multiplex PCR and sequencing using Ion Ampliseq™ technology. The author’s panel “­Diabetes Mellitus” included 28 genes (13 candidate genes of MODY and other genes associated with DM). Results: 13 heterozygous mutations were identified in 16 probands and 9 relatives. The majority of mutations were detected in patients with PNDM (18.75%) and in patients with an onset of DM at the age of 7–12 months (9.6%). Mutations in the INS gene were detected in 2 patients (0.3%) in the group with the MODY phenotype. Mutations in the INS gene were not detected in patients with transient NDM (TNDM). Analysis of clinical data in patients with PND and onset of diabetes at the age of 7–12 months did not show significant differences in the course of the disease. The clinical characteristics of the cases of MODY10 and diabetes caused by a mutation in the intron of the INS gene are reported in details. Conclusion: The role of INS gene mutations in NDM, MODY, and DM with an onset at the age of 7–12 months was analyzed in a large group of patients. The clinical characteristics of DM due to a mutation in the intron of the INS gene are reported for the first time in the Russian Federation.

Congenital hypothyroidism is an actual clinical problem in pediatric practice. Previous clinical guidelines were published in 2014. The presented clinical recommendations are based on articles published from January 2013 to early 2020. The consensus guidelines include such sections as results of neonatal screening, diagnostics and criteria for treatment, lifelong follow-up, genetics of congenital hypothyroidism, family genetic counselling. The key points of new congenital hypothyroidism guidelines were commented by pediatric endocrinologists of Russians.

Backgraund: Children with type 1 diabetes mellitus (T1DM) need more insulin late in the evening (reverse dawn phenomenon (RDP)), and adolescents need more insulin yearly in the morning (dawn phenomenon (DP)); these cause blood glucose variability. Modern long acting insulin analogues allow to achieve satisfactory glycemic control. Aims: To study the characteristics of insulin therapy in children and adolescents with T1DM using insulin analogues detemir and degludec to overcome blood glucose variability caused by DP and RDP in different age periods. Materials and methods: We analyzed medical documents of 200 patients using detemir, admitted to pediatric endocrinology department in 2013–2019, at mean age 9.0 years (5.4; 13.0), with T1DM for 1.3 years (0.5; 3.0); and medical documents of 50 patients switched to degludec in 2018–2019 at mean age 12.0 years (10.5; 14.5) with T1DM for 3.0 years (1.5; 6.0). Before degludec they were on intensive insulin therapy with glargine (22), detemir (26), or insulin pump (2); 16 patients (32%) presented with clinical characteristics of DP, and 5 (10%) — RDP. Results: 67 children of 108 (62%) aged 1–9 years had redistribution of detemir doses to daytime; 58 adolescents of 92 (63%) aged 10–17 лет — to nighttime. Patients switched to degludec demonstrated decrease in HbA1с from 8.7% (7.8; 9.9) to 8.0% (7.4; 9.0) (р<0.001); fasting blood glucose from 9.8 mmol/l (7.4; 11.7) to 7.7 mmol/l (6.4; 8.6) (р<0.001); within-day variability from 35.2% (31.6; 40.9) to 23.5% (19.7; 28.6) (р<0.001); daily insulin dose from 0.98 U/kg/day (0.82; 1.14) to 0.87 U/kg/day (0.75; 1.07) (р=0.002). Sub-groups of patients with DP and RDP demonstrated decrease in fasting blood glucose (from 11.5 mmol/l (9.8; 13.8) to 7.5 mmol/l (6.6; 9.1) (р<0.001)), and late evening blood glucose (from 11.0 mmol/l (10.2; 11.2) to 8.0 mmol/l (6.7; 9.5) (р= 0.03)) correspondently. Achieved levels of glycemic control did not differ between sub-groups of patients initially using glargine or detemir. Conclusions: Compensation of T1DM may be complicated due to DP and RDP. Switching to degludec allowed to achieve better glycemic control and lowering of blood glucose variability caused by DP and DRP.

The thyroiditis in children are urgent problem of pediatric endocrinology due to the widespread occurrence and characterized by clinical and pathogenetic heterogeneity. The developed clinical guidelines are the main working tool of the practitioner. They briefly and structurally present the main information about the epidemiology and modern classification of thyroiditis, methods of their diagnosis and treatment based on the principles of evidence-based medicine.