Background. An urgent and problematic issue in medicine today, in addition to the acute manifestation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, are the consequences of coronavirus disease 2019 (COVID-19), the so-called post-COVID syndrome (PCS). Currently, leading medical research institutions around the world are studying the causes, frequency and symptoms of PCS in both adults and children. Aim: to review the literature on the incidence and manifestations of post-COVID syndrome in children in order to draw the attention of medical professionals to the problem of post-COVID syndrome and its symptoms from various body systems. Materials and ­methods. The literature search was conducted in the PubMed and Google Scholar databases using the following keywords: “SARS-CoV-2 or COVID-19” and “post-COVID”, “long COVID”, “diabetes mellitus” and “in children”. Ukrainian literature search was conducted in the Google Scholar database using the following keywords: “SARS-CoV-2 or COVID-19” and “post-COVID”, “diabetes mellitus” and “in children”. The authors of the article reviewed the titles and abstracts of the found articles to select relevant publications. ­Results. The article provides data from the literature on PCS in children: definition of post-COVID syndrome in children, incidence, possible causes, pathogenesis and risk factors for the development of PCS. Signs of somatic, psychological and endocrinological manifestations of PCS are also given. The greatest attention is paid to the onset of type 1 diabetes mellitus (T1DM) in children after suffering ­COVID-19. It is noted that the frequency of T1DM in the pediatric population in the post-COVID period has almost doubled, to 0.043 versus 0.025 %. Global rate of new cases of T1DM in children in 2020 grew to 32.39 per 100,000 children compared to 19.73 per 100,000 children in 2019. Probable causes of diabetes after ­COVID-19 are direct cytolysis of pancreatic β-cells affected by the virus, and autoimmune reaction. A clinical case of diabetes mellitus in a young child as a possible manifestation of the PCS is provided. Conclusions. 1. The problem of PCS with various clinical manifestations in children is relevant and quite common. 2. PCS can deve­lop not only in children with acute manifestations of COVID-19, but also in children with asymptomatic course. 3. Along with the most frequent somatic and psychological manifestations of COVID-19 in children, endocrinopathy may occur, such as diabetes mellitus.

616.61-053.2:575:576.5

The prevalence of dysmetabolic nephropathies in children is increasing from year to year, representing a significant problem in the overall structure of kidney diseases in pediatric age. Despite numerous studies dedicated to the issue of dysmetabolic nephropathies in children, the role of epigenetic factors in the pathogenesis of dysmetabolic nephropathy with calcium oxalate crystalluria remains insufficiently explored.
Aim — to identify the leading epigenetic factors in the pathogenesis of dysmetabolic nephropathy with calcium oxalate crystalluria in children. Materials and methods. The data from the medical histories and outpatient records of 173 children were studied. Each child was additionally
examined by narrow specialists of different profiles. Three groups were formed from the examined children: Group I — children with a complicated course of dysmetabolic nephropathy and a history of inflammatory processes in the urinary system (52 children), Group II — children with dysmetabolic nephropathy with persistent crystalluria (56 children) and the Control group, which included 65 healthy children.
Results. The most significant prenatal epigenetic factors are the threat of early miscarriage, gestosis of the first and second halves of pregnancy, maternal anemia during pregnancy, parental alcohol and tobacco use, mother's work on computer during pregnancy, presence of maternal
chronic diseases, parental exposure to industrial dust and noise, and heavy physical work of mother leading to fetal hypoxia.
Conclusion. The most significant postnatal epigenetic factors influencing children's susceptibility to a more severe course of dysmetabolic
nephropathy included low birth weight, early artificial feeding, frequent acute respiratory infections, atopic diathesis, and physiological jaundice
in the first year of life, as well as the presence of concomitant diseases such as chronic tonsillitis, dental caries, frequent acute respiratory infections, chronic gastritis, atopy, and chronic cholecystitis later in life. The study was carried out in accordance with the principles of the Declaration of Helsinki. The study protocol was approved by the Local Ethics Committee of these institutions. The informed consent of the children's parents was obtained for the research. No conflict of interests was declared by the authors. 

УДК 616.831.71-009.26-056.7+616.16-007.64:575.224.2 

Провести молекулярно-генетичне дослідження експансії тринуклеотидних повторів гена андрогенового рецептора AR в осіб з підозрою на спинобульбарну м’язову атрофію (синдром Кеннеді). Методи. Клініко-генеалогічний, метод диференційної діагностики, виділення та очищення ДНК, молекулярно-генетичні: полімеразна ланцюгова реакція, електрофорез в агарозному гелі. Результати. Проведено молекулярно-генетичне дослідження експансії тринуклеотидних повторів гена андрогенового рецептора AR у 30 осіб з підозрою на синдром Кеннеді. У 5 пробандів досліджуваної групи встановлено 38 CAG-повторів (верхня межа норми) та у 27 обстежуваних пацієнтів кількість CAG-повторів не перевищувала 37 (норма). Серед обстеженої групи пацієнтів знайдено родину, в якій у трьох чоловіків встановлено 49 CAG-повторів у гені AR, що засвідчило наявність синдрому Кеннеді. Висновки. Синдром Кеннеді – рідкісне Х-зчеплене рецесивне захворювання, що потребує розробки специфічних біомаркерів для з’ясування патогенного процесу та полегшення ранньої діагностики.

Aim. To perform a molecular genetic study of CAG-repeat expansion in androgen receptor gene AR in individuals with suspected spinal and bulbar muscular atrophy (Kennedy’s syndrome). Methods. Clinical and genealogical, method of differential diagnosis, DNA isolation and purification, molecular genetic: polymerase chain reaction, electrophoresis in agarose gel. Results. A molecular genetic study of trinucleotide CAG-repeats expansion in androgen receptor gene in 30 people with suspected Kennedy’s syndrome was performed. In 5 probands of the study group, 38 CAG repeats (the upper limit of the norm) were established and in 27 examined patients, the number of CAG repeats did not exceed 37 (the norm). Among the examined group of patients, was found a family in which three men had 49 CAG repeats in the AR gene, which confirmed the presence of Kennedy’s syndrome. Conclusions. Kennedy’s syndrome is a rare X-linked recessive disease that requires the development of specific biomarkers to clarify the pathogenic process and facilitate early diagnosis.

УДК 616.988:578.834-06-053.2

Мультисистемний запальний синдром, асоційований із COVID-19 у дітей, є актуальною проблемою сьогодення. Мета роботи – ознайомити з особливостями перебігу та тактикою ведення пацієнтів дитячого віку із мультисистемним запальним синдромом, асоційованим із COVID-19 (MIS-C), проілюструвати власними клінічними спостереженнями. Матеріали і методи. Конкретні клінічні випадки з оцінкою клінічних симптомів, лабораторних показників, результатів додаткових обстежень та їх динаміки. Результати. Проаналізовано клінічні випадки, визначено особливості перебігу, складності діагностики, результати лікування. Висновки. MIS-C є складною клінічною проблемою, вимагає мультидисциплінарного підходу в питаннях діагностики та лікування.

In accordance to Rome IV Criteria irritable bowel syndrome (IBS) is classified into four subtypes: IBS with predominant constipation (IBS-C), IBS with predominant diarrhea (IBS-D), with mixed bowel habits (IBS-M) or IBS, unsubtyped. Some authors distinguish a post-infectious subtype of IBS, in which an acute episode of infectious gastroenteritis is a trigger of the disorder. In all the other cases, mostly psycho-emotional stress is the trigger factor, with this variant being defined as stress-associated subtype of IBS.  

Aim: to study the peculiarities of the formation and course of IBS in children, depending on the trigger factor. A total of 54 patients aged 6-12 years with a verified diagnosis of IBS according to Rome criteria IV have been examined. The trigger factor of the onset of IBS was established by the interrogation of patients and their parents. The levels of trait anxiety and somatization were assessed by Children's Form of the Manifest Anxiety Scale (CMAS) questionnaire and Somatoform Symptom Screening (SOMS) test respectively. The Catechol-O-methyltransferase (COMT) gene val158met polymorphism was estimated by the polymerase chain reaction. Enzyme immunoassay Ridascreen Calprotectin (R-Biopharm AG, Germany) was used for the quantitative determination of calprotectin in stool samples.

Results. We have diagnosed post-infectious subtype of IBS in 30 children. In this group we have found significantly higher concentration of fecal calprotectin (60.0 (35.6; 129.0) vs 31.2 (21.1; 58.7 mkg/g of feces)), which is consistent with pathogenesis of this subtype of IBS. On the contrary, we have discovered that psycho-emotional stress was the trigger factor of the onset of IBS in 22 patients (stress-associated subtype of IBS). Children with stress-associated IBS had higher levels of trait anxiety (25.1±5.7 vs. 18.7±6.4) and somatization (11.1 ± 4.0 vs. 8.6 ± 3.1) in comparison to patients with post-infectious subtype of the disorder. Furthermore, the analysis of the COMT gene polymorphism revealed, that almost the half patients (48%) with stress-associated IBS had 472 AA (Met/Met) genotype. Met/Met carriers have genetically determined low enzymatic activity of COMT, which may lead to decreased elimination of catecholamines and is associated with chronic stress. In contrast, only 31% of children with post-infectious subtype of IBS were found to have 472 AA (Met/Met) genotype.

Conclusions. Our study suggests that not only predominant bowel habit, but also trigger factor in the development of IBS determine the heterogeneity of the disorder. This approach may be used for classification of IBS in children, as it dictates treatment strategy.