OBJECTIVE:We describe the clinical and genetic characteristics of fetuses and infants diagnosed with tuberous sclerosis complex (TSC) in our centre, prenatally or neonatally, for a better understanding of the benefits of early screening. METHODS:In this retrospective study, we analysed the data on one fetus and nine infants with a definitive TSC diagnosis by genetic criteria (five patients carrying TSC1 variants and 5 patients carrying TSC2 variants). We explored the differences between phenotypes of patients carrying TSC1 and TSC2 pathogenic variants. RESULTS:The most common initial presenting features of TSC were cardiac rhabdomyomas (CRs) that were observed in nine out of ten patients. The most common postnatal features, besides CR, were presented with subependymal nodules-in five patients, and hypomelanotic macules-in four patients. In total, 10 variants causing TSC were detected in this study, including 5 novel variants. We demonstrated that patients with TSC2 variants had earlier onset and more severe clinical manifestations compared with patients carrying TSC1 variants. CONCLUSION:Early diagnosis of TSC improves genetic counselling and perinatal management.
Background: The reduction in next-generation sequencing (NGS) costs allows for using this method for newborn screening for monogenic diseases (MDs). In this report, we describe a clinical case of a newborn participating in the EXAMEN project (ClinicalTrials.gov Identifier: NCT05325749). Methods: The child presented with convulsive syndrome on the third day of life. Generalized convulsive seizures were accompanied by electroencephalographic patterns corresponding to epileptiform activity. Proband WES expanded to trio sequencing was performed. Results: A differential diagnosis was made between symptomatic (dysmetabolic, structural, infectious) neonatal seizures and benign neonatal seizures. There were no data in favor of the dysmetabolic, structural, or infectious nature of seizures. Molecular karyotyping and whole exome sequencing were not informative. Trio WES revealed a de novo variant in the KCNJ9 gene (1:160087612T > C, p.Phe326Ser, NM_004983), for which, according to the OMIM database, no association with the disease has been described to date. Three-dimensional modeling was used to predict the structure of the KCNJ9 protein using the known structure of its homologs. According to the predictions, Phe326Ser change possibly disrupts the hydrophobic contacts with the valine side chain. Destabilization of the neighboring structures may undermine the formation of GIRK2/GIRK3 tetramers necessary for their proper functioning. Conclusions: We believe that the identified variant may be the cause of the disease in this patient but further studies, including the search for other patients with the KCNJ9 variants, are needed.
Background Inefficiency of in vitro fertilization (IVF) programs can be caused by implantation failures. The uterine microbiota can influence the implantation process. However, it still remains unclear whether opportunistic microorganisms detected in the endometrium have a negative impact on the implantation success. The aim of our study was to evaluate the influence of the uterine microbiota on the embryo implantation success in patients undergoing assisted reproductive technologies. Methods The study included 130 women diagnosed with infertility. The patients were divided into three groups: group I included women with the first IVF attempt (n = 39); group II included patients with recurrent implantation failure following embryo transfer with ovarian stimulation (n = 27); group III consisted of women with recurrent implantation failure following frozen-thawed embryo transfer (n = 64). We performed microbiological examination of the embryo transfer catheter which was removed from the uterine cavity after embryo transfer; cervical discharge of all the patients was studied as well. Thirty patients were selected for metagenomic sequencing. Results The study showed that the uterine cavity is not free of microorganisms. A total of 44 species of microorganisms were detected: 26 species of opportunistic organisms and 18 species of commensals (14 species of lactobacilli and 4 species of bifidobacteria). Obligate anaerobic microorganisms and Gardnerella vaginalis were detected more frequently in group I compared to group III (strict anaerobes—15.4 and 1.6%; G. vaginalis—12.8 and 1.6%, respectively) ( p < 0.05). However, this fact did not have a negative influence on the pregnancy rate: it was 51.3% in group I, it was 29.6% and 35.9% in women with recurrent implantation failures, respectively. Conclusion Opportunistic microorganisms which were revealed in low or moderate titers (10 3 –10 5 CFU/ml) in the uterine cavity and cervical canal did not affect the pregnancy rate in the women in the study groups. The microflora of the uterine cavity and cervical canal differed in qualitative composition in 87.9% of patients, therefore, we can suggest that the uterine cavity may form its own microbiota. The microbiota of the uterine cavity is characterized by fewer species diversity compared to the microbiota of the cervical canal.
Background: Intellectual disability with developmental delay is the most common developmental disorder. However, this diagnosis is rarely associated with congenital cardiomyopathy. In the current report, we present the case of a patient suffering from dilated cardiomyopathy and developmental delay. Methods: Neurological pathology in a newborn was diagnosed immediately after birth, and the acquisition of psychomotor skills lagged behind by 3–4 months during the first year of life. WES analysis of the proband did not reveal a causal variant, so the search was extended to trio. Results: Trio sequencing revealed a de novo missense variant in the CAMK2D gene (p.Arg275His), that is, according to the OMIM database and available literature, not currently associated with any specific inborn disease. The expression of Ca2+/calmodulin-dependent protein kinase II delta (CaMKIIδ) protein is known to be increased in the heart tissues from patients with dilated cardiomyopathy. The functional effect of the CaMKIIδ Arg275His mutant was recently reported; however, no specific mechanism of its pathogenicity was proposed. A structural analysis and comparison of available three-dimensional structures of CaMKIIδ confirmed the probable pathogenicity of the observed missense variant. Conclusions: We suggest that the CaMKIIδ Arg275His variant is highly likely the cause of dilated cardiomyopathy and neurodevelopmental disorders.
The authors analyzed available data in modern literature on the role of genetic testing for mutations in genes responsible for predisposing to hereditary cancers of reproductive organs in women. They are looking at data on the importance of using genetic testing in clinical practice to predict the disease development, need for follow-up monitoring in the presence of mutation load, and determination of combined chemotherapy policy for malignant neoplasms.
A strain of obligately anaerobic, spore-forming, Gram-positive rods was isolated from child faeces and characterized both phenotypically and genotypically. Phylogenetic analysis based on 16S rRNA gene and whole genome sequencing revealed the strain to represent a member of the family Ruminococcaceae distant from described species and genera. The strain was moderately saccharolytic with mannose as the preferred substrate and produced lactic acid, acetic acid and H-2 as the end products. The major cellular long-chain fatty acids were C-16.0 and C-16.0 aldehyde. The genomic DNA G+C content was 52.3 mol%. On the basis of chemotaxonomic and genomic properties it was concluded that the strain represents a novel species in a new genus within the family Ruminococcaceae, for which the name Hydrogeniiclostidium mannosilyticum gen. nov., sp. nov. is proposed. The type strain of Hydrogeniiclostidium mannosilyticum is ASD2818(T) (=VKM B-3268(T)=JCM 33295(T)).
Проанализированы современные данные о роли генетического тестирования мутаций в генах, ответственных за предрасположенность к наследственному раку половых органов у женщин. Представлены данные о важности использования генетического тестирования в клинической практике для прогнозирования развития заболевания, необходимости последующего мониторинга при наличии мутационной нагрузки и выбора тактики комбинированной терапии при злокачественных новообразованиях The authors analyzed available data in modern literature on the role of genetic testing for mutations in genes responsible for predisposing to hereditary cancers of reproductive organs in women. They are looking at data on the importance of using genetic testing in clinical practice to predict the disease development, need for follow-up monitoring in the presence of mutation load, and determination of combined chemotherapy policy for malignant neoplasms.
Неинвазивный пренатальный ДНК-скрининг (НИПС) начал использоваться в клинической практике в 2011г. и в настоящее время широко применяется, как и в мире, так и в России. Проанализирована встречаемость «редких» анеуплоидий при проведении полногеномного НИПС у 2061 пациенток и исходы беременностей при наличии таких результатов. Показано, что при анализе всего генома для полногеномного варианта НИПС можно получить дополнительную информацию, важную как для прогноза течения беременности, так и для прогноза плода. Это позволяет выделить дополнительную небольшую группу беременных, которым может быть рекомендовано более пристальное наблюдение в течение беременности или проведение дополнительных диагностических процедур. Однако для определения чувствительности и специфичности определения «редких» анеуплодий и CNV в настоящий момент недостаточно данных. Noninvasive prenatal DNA screening (NIPS) is getting more widespread in clinical practice in Russia and all around the world. The use of shallow whole-genome sequencing for NIPS allows analysis of all chromosome aneuploidies; hence there are large-scale studies only on test performance on common trisomies. This study aimed to analyze the prevalence of «rare» aneuploidies using whole-genome NIPS and pregnancy outcomes in case of a high risk of «rare» aneuploidy. Noninvasive prenatal DNA screening was performed using in house developed protocol. We have analyzed 2061 samples. In 8 cases (0.4%) high-risk of rare trisomy was detected (3 - trisomy 7, 2 - trisomy 8, 1 - trisomy 10, 2 - trisomy 15). We have identified two cases of a high risk of large copy number variations (CNV). For all of the high-risk cases, we have information about pregnancy outcomes. Thereby whole-genome analysis will enable us to get the additional information and reveal pregnancies in need of further observation or testing. Hence there is not enough data for the estimation of sensitivity and specificity of detection of «rare» aneuploidies.
Своевременное обнаружение анеуплоидий плода очень важно в клинической практике. В настоящее время идет активное развитие аналитических методов с применением высокопроизводительного секвенирования. Благодаря неинвазивному пренатальному ДНК-скринингу (НИПС) достоверные результаты можно получать на сроке 9–11 недель. Описан клинический случай применения НИПС и дальнейшей верификации полученных результатов. С помощью методов высокопроизводительного секвенирования, микроматричного анализа амниотической жидкости и цитогенетического кариотипирования у плода обнаружен высокий риск хромосомных перестроек в коротком плече 4-й и 12-й хромосом. Результаты были подтверждены с помощью молекулярного кариотипирования. Проверка родителей позволила выявить у матери сбалансированные хромосомные перестройки в 4-й и 12-й хромосомах. Данный случай демонстрирует преимущества полногеномного подхода перед таргетным при проведении НИПС.
Timely detection of fetal aneuploidy is an important aspect of clinical practice. At present, analytical techniques involving high-throughput sequencing are on the rise. Noninvasive prenatal testing (NIPT) ensures reliable results as early as week 9–11 into pregnancy. This article describes a clinical case of NIPT application and further verification of its results. Using next-generation sequencing, the microarray analysis of cell-free DNA in the amniotic fluid and the cytogenetic analysis of fetal chromosomes, a high risk of chromosomal rearrangements was detected in the short arms of chromosomes 4 and 12. This prediction was verified by molecular karyotyping conducted in both parents. The mother was found to be a balanced carrier of translocations between chromosomes 4 and 12. This case demonstrates the advantages of a whole-genome approach to NIPT over targeted-based.
We report here a draft genome sequence of Megasphaera sp. ASD88, a strain from the intestinal microbiota of a child with autism spectrum disorder, representing a previously undescribed species of the genus Megasphaera. The assembled sequence consists of 88 scaffolds, and the total size is 2.59 Mb.
Introduced into clinical practice in 2011, non-invasive prenatal testing (NIPT) allows detection of chromosomal aneuploidies in the fetus using maternal blood samples. Multiple studies have shown that one of the key factors affecting the result of this test is the fetal DNA fraction. The aim of this work was to develop a method capable of measuring the fetal DNA fraction based on targeted SNP sequencing. We selected polymorphisms with high frequency of heterozygous genotype from the international HapMap database. To estimate the frequency of these polymorphisms in the Russian population, we used 827 DNA donor samples. Fetal DNA fraction was measured in 87 plasma samples of pregnant women. Sequencing was performed on Ion Proton and Ion S5. We determined the frequencies of the studied polymorphisms in the pooled samples and compared the data on 53 SNPs in the pooled and 87 individual samples. The median difference was 3.4%. The correlation between the results obtained by targeted SNP sequencing and Y chromosome read count was 0.7. Thus, the proposed method can be used to estimate the fetal DNA fraction using SNP genotyping regardless of the fetus's sex.
Неинвазивный пренатальный ДНК-скрининг (НИПС) анеуплоидий по крови матери применяется для выявления хромосомных анеуплоидий (ХА) с 2011 г.Многочисленные клинические исследования показали, что важным параметром при проведении
The present study aimed to determine frequencies of mutations in the phenylalanine hydroxylase gene (PAH) in unrelated children (n = 71) diagnosed with phenylketonuria, who presented to Morozovskaya Children's City Clinical hospital (Moscow) over the period from 2015 to 2016. The patients were tested for the most common PAH mutations using the original real-time PCR-based technique for the identification of nucleotide variants; additionally, next generation sequencing (NGS) was performed on the unidentified genotypes. The original PCR-based technique allowed us to effectively identify 83 % of the pathogenic allelic variants in the sample. Using the combination approach (real-time PCR + NGS), we found mutations in both alleles of PAH in 66 of total 71 patients. Altogether, 26 pathogenic PAH mutations were identified, the most common being p.R408W (47.9 %) and p.R261Q (9.9 %). Frequencies of mutations common for the Russian population, such as IVS10nt546, IVS12+1G>A, p.R158Q, p.Y414C, and IVS4+5G>T, ranged from 4.2 to 2.8 %. Half of the identified variants accounted for the total frequency of < 10 %. Sequencing of PAH revealed a few functional mutations previously unreported for Moscow region residents, including p. D222Terfs, p.R111Ter, p.F161S, p.G188D, p.R270K, p.L311P, p.F55L, p.F55Leufs, IVS1+5G>T, and IVS8-7A>G. It could be reasonable to include mutations p. D222Terfs and p.R111Ter (carrier frequency of 2.1 %) in PCR testing panels. The data obtained in our study can also be used in the development of genetic tests for phenylketonuria.
Ataxia-telangiectasia (A-T), or Louis-Bar syndrome, is a rare neurodegenerative disorder associated with immunodeficiency. For families with at least one affected child, timely A-T genotyping during any subsequent pregnancy allows the parents to make an informed decision about whether to continue to term when the fetus is affected. Mutations in the ATM gene, which is 150 kb long, give rise to A-T; more than 600 pathogenic variants in ATM have been characterized since 1990 and new mutations continue to be discovered annually. Therefore, limiting genetic screening to previously known SNPs by PCR or hybridization with microarrays may not identify the specific pathogenic genotype in ATM for a given A-T family. However, recent developments in next-generation sequencing technology offer prompt high-throughput full-length sequencing of genomic fragments of interest. This allows the identification of the whole spectrum of mutations in a gene, including any novel ones. We report two A-T families with affected children and current pregnancies. Both families are consanguineous and originate from Caucasian regions of Russia and Azerbaijan. Before our study, no ATM mutations had been identified in the older children of these families. We used ion semiconductor sequencing and an Ion AmpliSeq™ Inherited Disease Panel to perform complete ATM gene sequencing in a single member of each family. Then we compared the experimentally determined genotype with the affected/normal phenotype distribution in the whole family to provide unambiguous evidence of pathogenic mutations responsible for A-T. A single novel SNP was allocated to each family. In the first case, we found a mononucleotide deletion, and in the second, a mononucleotide insertion. Both mutations lead to truncation of the ATM protein product. Identification of the pathogenic mutation in each family was performed in a timely fashion, allowing the fetuses to be tested and diagnosed. The parents chose to continue with both pregnancies as both fetuses had a healthy genotype and thus were not at risk of A-T.
Staphylococcus epidermidis представитель нормальной микрофлоры человека, способный вызывать опасные заболевания у новорожденных с очень низкой и экстремально низкой массой тела при рождении. Различные штаммы S. epidermidis обладают разным спектром генов, ассоциированных с их резистентностью к антимикробным препаратам и патогенностью. По результатам анализа данных полных геномных секвенирований четырнадцати штаммов S. epidermidis изучено генетическое разнообразие штаммов, циркулирующих в отделении реанимации и интенсивной терапии новорожденных НЦАГиП им. В. И. Кулакова. Выявлена принадлежность штаммов к восьми сиквенс-типам, из которых чаще встречались ST2 и ST59, принадлежащие к единому клональному комплексу СС2. К данному клональному комплексу относились 10 из 14 штаммов. Показано, что изученные штаммы обладали широким спектром генов резистентности к антимикробным препаратам. Обнаружено 15 различных генов, обуславливающих резистентность штаммов к аминогликозидам, бета-лактамным антибиотикам, фузидиевой кислоте, макролидам, линкозамидам, стрептограмину В, тетрациклину и триметоприму. Выявлены гены, ассоциированные с патогенностью (аае, atlE, аар, embp), встречающиеся в геномах изученных штаммов с разной частотой. В геномах девяти штаммов был обнаружен инсерционный элемент IS256, а в геномах семи штаммов гены iса-оперона, отвечающего за синтез белков матрикса биопленок.
Staphylococcus epidermidis is a member of the normal bacterial flora of humans capable of causing potentially dangerous diseases in neonates with very or extremely low birth weight. The number of genes responsible for virulence and antibiotic resistance may vary in different S. epidermidis strains. We sequenced isolates of S. epidermidis to explore genetic diversity of 14 strains circulating in the Neonatal Intensive Care Unit of Kulakov Research Center for Obstetrics, Gynecology and Perinatology. Among the studied strains, 8 sequence types were identified, the most frequent being ST2 and ST59, both of which belong to the clonal complex CC2. Of 14 studied strains, 10 were of CC2 type. The studied strains revealed a variety of genes responsible for antibiotic resistance. We found 15 genes that provided resistance to aminoglycosides, beta-lactam antibiotics, fusidic acid, macrolides, lincosamides, streptogramin B, tetracycline, and trimethoprim. We identified a number of genes associated with virulence (aae, atlE, aap, embp), whose frequency in the studied isolates was varied. The insertion element IS256 was detected in 9 strains, and 7 strains revealed the presence of the ica-operon responsible for the biosynthesis of the biofilm matrix proteins.