Results of the screening of disease causative mutations in congenital hypothyroidism (CH) vary significantly, depending on the sequence strategy, patients’ inclusion criteria and bioinformatics. The objective was to study the molecular basis of severe congenital hypothyroidism, using the next generation sequencing (NGS) and the recent guidelines for assessment of sequence variants. 243 patients with CH (TSH levels at neonatal screening or retesting greater than 90 mU/l) and 56 control subjects were included in the study. A custom NGS panel targeting 12 CH causative genes was used for sequencing. The sequence variants were rated according to American College of Medical Genetics and Genomics (ACMG) guidelines. In total, 48 pathogenic, 7 likely pathogenic and 57 variants of uncertain significance were identified in 92/243 patients (37.9%), while 4 variants of uncertain significance were found in 4/56 control subjects (7.1%). 13.1% (12/92) of the cases showed variants in ‘thyroid dysgenesis’ (TD) genes: TSHR, n = 6; NKX2-1, n = 2; NKX2-5, n = 1; PAX8, n = 3. The variants in ‘dyshormonogenesis’ (DH) genes were found in 84.8% (78/92) of cases: TPO, n = 30; DUOX2, n = 24; TG, n = 8; SLC5A5, n = 3; SLC26A4, n = 6; IYD, n = 1. 8 patients showed oligonenic variants. The majority of variants identified in DH genes were monoallelic. In contrast to earlier studies demonstrating the predominance of TD in severe CH, the majority of variants identified in our study were in DH genes. A large proportion of monoallelic variants detected among DH genes suggests that non-mendelian mechanisms may play a role in the development of CH.

The aim of this study was to assess the correlations of clinical features of patients with moderate and severe courses of COVID-19, comorbidity (endocrine, autoimmune, cardiovascular, oncological, and pulmonary diseases), and alleles of the HLA class II system genes. One hundred COVID-19 patients hospitalized in the Endocrinology Research Centre, Moscow, Russia, were analyzed for age, gender, smoking, comorbidity, and invasive mechanical ventilation. Computer tomography was used to assess the severity of the disease. HLA-DRB1, HLA-DQA1, and HLA-DQB1 alleles were identified in samples from 100 patients and samples from 327 randomly selected individuals collected in the prepandemic period (control group). There was no association of gender, age, weight, body mass index, smoking, and comorbidity with the severity of COVID-19. Allele DQB1*06:02-8 was more common in patients (p < 0.00005), and DQB1*06:01 and DQB1*05:03 were more common in the control group (p < 0.00005, and p = 0.0011, respectively). DQB1*06:02-8 can probably be considered as predisposing to moderate and severe COVID-19, and DQB1*06:01 can be considered as protective. No association of these alleles with comorbidity was found. Our results suggest that carriers of predisposing alleles, with cardiovascular and non-autoimmune endocrine diseases, should take more stringent preventive measures, and if infected, a more aggressive COVID-19 treatment strategy should be used.

Aims. To demonstrate the principles of personalized treatment of diabetes for example the most common MODY subtypes (1-3) identified by NGS Methods. We study 312 patients aged from 3 months to 25 years (162 boy/150 girls) with suspected MODY. A targeted next-generation sequencing approach (IonTorrent platform) was used for sequencing of monogenic form of diabetes mellitus candidate 28genes (13 MODY genes-candidates and other genes, associated with diabetes mellitus). Clinical and biochemicalphenotypes of the patients were compared with the type of mutations. Previously undescribed nonsynonymous mutations were considered as «probably pathogenic» with the minor allele frequency of <0.1% and «pathogenic» assessment in ANNOVAR database. Results. We selected group of patients with mutations in the most common genes-candidates (GCK; HNF1A; HNF4A):99GCK gene mutations detectedin the 129 probands (61,1%) and 77 relatives, in HNF1A – 20 mutations in the 19 probands(9,0%) and 14 relatives, in HNF4A – 8 mutations in 9the probands (4,3%) and 3 relatives. The current therapy wasmodificated account the genotype and have been evaluated its effectiveness. Conclusion. Molecular genetic confirmation of the monogenic nature of metabolic carbohydratedisorders is the basis of personalized therapy of diabetes.

Objective — the research was aimed at studying clinical and molecular genetic characteristics of the most common subtypes of MODY (1—3) detected by NGS. Material and methods. The study included 312 patients (162 boys and 150 girls) aged 3 months to 25 years with suspected MODY. Inclusion criteria were as follows: carbohydrate metabolism disorders of varying severity, negative titer of ICA, IA2, and GAD autoantibodies, preserved secretion of endogenous insulin. NGS technique was used for molecular genetic studies. Custom DNA Panel was used for the multiplex PCR and sequencing using the Ion Ampliseq technique. Custom Diabetes Panel included 28 genes (13 MODY candidates genes and other diabetes-associated genes). Non-synonymous mutations that were not previously described were rated as «probably pathogenic» if they had minor allele frequency of <0.1% and «pathogenic» when assessed against the ANNOVAR database. Results. Mutations in MODY candidate genes were detected in 178 (57.1%) probands. Of these, 99 mutations in GCK99 gene were found in 129 (41.4%) probands and 77 relatives, 20 mutations in HNF1A gene were found in 19 (6.1%) probands and 14 relatives, 8 mutations in HNF4A gene — in 9 (2.9%) probands and 3 relatives. All detected mutations were heterozygous. MODY1 subtype was not previously described in the Russian Federation. Conclusions. The Russian population is dominated by MODY2 subtype. Only MODY2 is characterized by typical clinical presentation. NGS is a highly effective method in the diagnosis of MODY.

MODY (Maturity-Onset diabetes of the young) is a heterogeneous group of disorders characterized by autosomal dominant type of inheritance and caused by genetic defects leading to dysfunction of pancreatic b-cells. Currently 13 candidate genes of MODY, and, respectively, 13 MODY subtypes are known. The final diagnosis can be established only on the basis of molecular genetic studies, which is the «gold standard» in the diagnosis of this disease. MODY2 and MODY3 are the most prevalent subtypes and were previously described in our country. Rare MODY subtypes have not been described in Russian literature. In this article we describe the first diagnosed case of MODY6 in Russia (a defect of the NEUROD1 gene, encoding neurogenic differentiation factor 1, which plays an important role in normal differentiation of β-cells of the pancreas and the regulation of transcription of the insulin gene). Molecular genetic study was conducted using the method of next-generation sequencing, has recently been widely used for genetic verification of monogenic diseases and, in particular, MODY. Technology of next-generation sequencing for diagnosing inherited disorders of carbohydrate metabolism in domestic practice used for the first time.