Meier-Gorlin syndrome (MGS) is a rare genetic developmental disorder that causes primordial proportional dwarfism, microtia, the absence of or hypoplastic patellae and other skeletal anomalies. Skeletal symptoms overlapping with other syndromes make MGS difficult to diagnose clinically. We describe a 3-year-old boy with short stature, recurrent respiratory infections, short-rib dysplasia, tower head and facial dysmorphisms who was admitted to the Tomsk Genetic Clinic to verify a clinical diagnosis of Jeune syndrome. Clinical exome sequencing revealed two variants (compound heterozygosity) in the ORC6 gene: c.2T>C(p.Met1Thr) and c.449+5G>A. In silico analysis showed the pathogenicity of these two mutations and predicted a decrease in donor splicing site strength for c.449+5G>A. An in vitro minigene assay indicated that variant c.449+5G>A causes complete skipping of exon 4 in the ORC6 gene. The parents requested urgent prenatal testing for MGS for the next pregnancy, but it ended in a miscarriage. Our results may help prevent MGS misdiagnosis in the future. We also performed in silico and functional analyses of ORC6 mutations and developed a restriction fragment length polymorphism and haplotype-based short-tandem-repeat assay for prenatal genetic testing for MGS. These findings should elucidate MGS etiology and improve the quality of genetic counselling for affected families.

Abnormal development of corpus callosum is relatively common and causes a broad spectrum of cognitive impairments in humans. We use acallosal Neurod2/6-deficient mice to study callosal axon guidance within the ipsilateral cerebral cortex. Initial callosal tracts form but fail to traverse the ipsilateral cingulum and are not attracted towards the midline in the absence of Neurod2/6. We show that the restoration of Ephrin-A4 (EfnA4) expression in the embryonic neocortex of Neurod2/6-deficient embryos is sufficient to partially rescue targeted callosal axon growth towards the midline. EfnA4 cannot directly mediate reverse signaling within outgrowing axons, but it forms co-receptor complexes with TrkB (Ntrk2). The ability of EfnA4 to rescue the guided growth of a subset of callosal axons in Neurod2/6-deficient mice is abolished by the co-expression of dominant negative TrkBK571N (kinase-dead) or TrkBY515F (SHC-binding deficient) variants, but not by TrkBY816F (PLCγ1-binding deficient). Additionally, EphA4 is repulsive to EfnA4-positive medially projecting axons in organotypic brain slice culture. Collectively, we suggest that EfnA4-mediated reverse signaling acts via TrkB-SHC and is required for ipsilateral callosal axon growth accuracy towards the midline downstream of Neurod family factors.

Miscarriage affects approximately 15% of clinically recognized pregnancies, and 1-3% of couples experience pregnancy loss recurrently. Approximately 50-60% of miscarriages result from chromosomal abnormalities, whereas up to 60% of euploid recurrent abortions harbor variants in candidate genes. The growing number of detected genetic variants requires an investigation into their role in adverse pregnancy outcomes. Since placental defects are the main cause of first-trimester miscarriages, the purpose of this review is to provide a survey of state-of-the-art human in vitro trophoblast models that can be used for the functional assessment of specific abnormalities/variants implicated in pregnancy loss. Since 2018, when primary human trophoblast stem cells were first derived, there has been rapid growth in models of trophoblast lineage. It has been found that a proper balance between self-renewal and differentiation in trophoblast progenitors is crucial for the maintenance of pregnancy. Different responses to aneuploidy have been shown in human embryonic and extra-embryonic lineages. Stem cell-based models provide a powerful tool to explore the effect of a specific aneuploidy/variant on the fetus through placental development, which is important, from a clinical point of view, for deciding on the suitability of embryos for transfer after preimplantation genetic testing for aneuploidy.

Skewed X-chromosome inactivation (sXCI) can be a marker of lethal genetic variants on the X chromosome in a woman since sXCI modifies the pathological phenotype. The aim of this study was to search for CNVs in women with miscarriages and sXCI. XCI was assayed using the classical method based on the amplification of highly polymorphic exon 1 of the androgen receptor (AR) gene. The XCI status was analysed in 313 women with pregnancy loss and in 87 spontaneously aborted embryos with 46,XX karyotype, as well as in control groups of 135 women without pregnancy loss and 64 embryos with 46,XX karyotype from induced abortions in women who terminated a normal pregnancy. The frequency of sXCI differed significantly between women with miscarriages and women without pregnancy losses (6.3% and 2.2%, respectively; p = 0.019). To exclude primary causes of sXCI, sequencing of the XIST and XACT genes was performed. The XIST and XACT gene sequencing revealed no known pathogenic variants that could lead to sXCI. Molecular karyotyping was performed using aCGH, followed by verification of X-linked CNVs by RT-PCR and MLPA. Microdeletions at Xp11.23 and Xq24 as well as gains of Xq28 were detected in women with sXCI and pregnancy loss.

Modeling 3D genome organisation has been booming in the last years thanks to the availability of experimental datasets of genomic contacts. However, the field is currently missing the standardisation of methods and metrics to compare predictions and experiments. We present 3DGenBench, a web server available at https://inc-cost.eu/benchmarking/, that allows benchmarking computational models of 3D Genomics. The benchmark is performed using a manually curated dataset of 39 capture Hi-C profiles in wild type and genome-edited mouse cells, and five genome-wide Hi-C profiles in human, mouse, and Drosophila cells. 3DGenBench performs two kinds of analysis, each supplied with a specific scoring module that compares predictions of a computational method to experimental data using several metrics. With 3DGenBench, the user obtains model performance scores, allowing an unbiased comparison with other models. 3DGenBench aims to become a reference web server to test new 3D genomics models and is conceived as an evolving platform where new types of analysis will be implemented in the future.

Human induced pluripotent stem cell (iPSC) line, ICGi040-A, was obtained from skin fibroblasts derived from a male patient with mosaic ring small supernumerary marker chromosome 4 (sSMS(4)) and infertility. ICGi040-A cells have karyotype 47,XY,+r(4) in 97% of cells and express a set of pluripotent markers, as well as are able to differentiate in vitro into derivatives of all three embryonic germ layers.

The development of cellular models for familial hypercholesterolemia (FH) is an important direction for creating new approaches to atherosclerosis treatment. Pathogenic mutations in the LDLR gene are the main FH source. We generated an iPSC line from peripheral blood mononuclear cells of the patient with compound heterozygous c.1246C > T/c.940 + 3_940 + 6del LDLR mutation. The resulting iPSC line with confirmed patient-specific mutations maintains a normal karyotype and a typical undifferentiated state, including morphology, pluripotent gene expression, and in vitro differentiation potential. This iPSC line can be further differentiated toward relevant cells to better understand FH pathogenesis.

The presence of an extra chromosome in the embryo karyotype often dramatically affects the fate of pregnancy. Trisomy 16 is the most common aneuploidy in first-trimester miscarriages. The present study identified changes in DNA methylation in chorionic villi of miscarriages with trisomy 16. Ninety-seven differentially methylated sites in 91 genes were identified (false discovery rate (FDR) < 0.05 and Δβ > 0.15) using DNA methylation arrays. Most of the differentially methylated genes encoded secreted proteins, signaling peptides, and receptors with disulfide bonds. Subsequent analysis using targeted bisulfite massive parallel sequencing showed hypermethylation of the promoters of specific genes in miscarriages with trisomy 16 but not miscarriages with other aneuploidies. Some of the genes were responsible for the development of the placenta and embryo (GATA3-AS1, TRPV6, SCL13A4, and CALCB) and the formation of the mitotic spindle (ANKRD53). Hypermethylation of GATA3-AS1 was associated with reduced expression of GATA3 protein in chorionic villi of miscarriages with trisomy 16. Aberrant hypermethylation of genes may lead to a decrease in expression, impaired trophoblast differentiation and invasion, mitotic disorders, chromosomal mosaicism and karyotype self-correction via trisomy rescue mechanisms.

Although half of hypertensive patients have hypertensive parents, known hypertension-related human loci identified by genome-wide analysis explain only 3% of hypertension heredity. Therefore, mainstream transcriptome profiling of hypertensive subjects addresses differentially expressed genes (DEGs) specific to gender, age, and comorbidities in accordance with predictive preventive personalized participatory medicine treating patients according to their symptoms, individual lifestyle, and genetic background. Within this mainstream paradigm, here, we determined whether, among the known hypertension-related DEGs that we could find, there is any genome-wide hypertension theranostic molecular marker applicable to everyone, everywhere, anytime. Therefore, we sequenced the hippocampal transcriptome of tame and aggressive rats, corresponding to low and high stress reactivity, an increase of which raises hypertensive risk; we identified stress-reactivity-related rat DEGs and compared them with their known homologous hypertension-related animal DEGs. This yielded significant correlations between stress reactivity-related and hypertension-related fold changes (log2 values) of these DEG homologs. We found principal components, PC1 and PC2, corresponding to a half-difference and half-sum of these log2 values. Using the DEGs of hypertensive versus normotensive patients (as the control), we verified the correlations and principal components. This analysis highlighted downregulation of β-protocadherins and hemoglobin as whole-genome hypertension theranostic molecular markers associated with a wide vascular inner diameter and low blood viscosity, respectively.

Familial hypercholesterolemia (FH) is an autosomal dominant disorder increasing premature cardiovascular diseases risk due to atherosclerosis. Pathogenic mutations in the LDLR gene cause most FH cases. Available treatments are effective not for all LDLR mutations. Testing drugs on FH cell models help develop new efficient treatments. We obtained an iPSC line from peripheral blood mononuclear cells of the patient with heterozygous p.Trp443Arg LDLR mutation. The iPSCs with confirmed patient-specific mutations express pluripotency markers, spontaneously differentiate into three germ layers and demonstrate normal karyotype. Patient-specific iPSCs-derived hepatocyte-like and endothelial cells are promising to develop new targeted therapies for FH.

Familial hypercholesterolemia (FH) is a monogenic disease, leading to atherosclerosis due to a high level of low-density lipoprotein cholesterol. Most cases of the disease are based on pathological variants in the LDLR gene. Hepatocyte-like and endothelial cells derived from individual iPSCs are a good model for developing new approaches to therapy. We obtained an iPSC line from peripheral blood mononuclear cells of the patient with compound heterozygous p.Ser177Leu/p.Cys352Arg mutation in LDLR using non-integrating vectors. The iPSCs with a confirmed patient-specific mutation demonstrate pluripotency markers, normal karyotype, and the ability to differentiate into derivatives of three germ layers.

Проблема идентификации в российских популяциях этноспецифических мутаций, ассоциированных с наследственными формами рака молочной железы, остается открытой. Технология высокопроизводительного секвенирования является методом выбора, однако существуют сложности интерпретации полученного массива данных при аннотировании их с использованием общепринятых баз данных. Так, для малоизученных популяций от 20 % молекулярных тестов сообщают о генетических вариантах неизвестного значения (Vus) или новых вариантах, которые ранее не были описаны. Для получения расширенной информации о вариантах высокопроизводительного секвенирования неизвестного значения необходимо использовать альтернативные подходы анализа данных. Материал и методы. Проведена реклассификация мутации неизвестного значения гена ТР53 с использованием базы данных activedrivedB, которая оценивает влияние мутаций на сайты посттрансляционных модификаций, и инструмента proteinpaint, который обеспечивает всестороннее и интуитивно понятное представление о геномных данных. Результаты. Мутация гена tp53 (rs1555526933) была обнаружена у молодой тувинки 44 лет с диагнозом РМЖ. В базе данных dbpubmed (rs1555526933, chr17:7579716, g>a, pro27leu) эта мутация является вариантом неизвестного значения (unknown significance) с отсутствием информации о частоте встречаемости минорного аллеля. Согласно данным инструмента activedriverdB, эта мутация расположена дистально в сайте посттрансляционной модификации белков, отвечающем за связывание с киназами, регулирующими гены клеточного цикла и др. (atm, cHeK2, cdK, mapK). Согласно данным proteinpoint, эта мутация находится в кодоне, где ранее была описана патогенная мутация гена tp53 p.leu26glnfster4 (Nm_000546.6 (tp53): c.77_80delinsaagaacgt (p.leu26fs), приводящая к формированию синдрома Ли – Фраумени (группа редких наследственных опухолевых заболеваний). Заключение. Впервые у пациентки (тувинский этнос) с ранним началом РМЖ и отягощенным онкологическим анамнезом описан вариант гена tp53 (rs1555526933), который может быть связан с синдромом наследственной предрасположенности к РМЖ, включая синдром Ли – Фраумени.

В современных популяциях система биотрансформации работает в условиях повышенной нагрузки, так как обеспечивает метаболизм не только широкого спектра эндогенных субстратов, но и различных ксенобиотиков, что может способствовать развитию заболеваний различных систем органов, а в ряде случаев приводить к формированию коморбидных состояний, при которых наблюдается усиленная работа системы метаболизма ксенобиотиков. В связи с этим большой интерес вызывает изучение вовлеченности полиморфизма генов метаболизма ксенобиотиков в формирование не только изолированной патологии, но и различных коморбидных состояний.Цель исследования: изучение вовлеченности полиморфного варианта rs4244285 гена CYP2C19, приводящего к синтезу нефункционального белка, в развитие как изолированной патологии, так и сочетанных заболеваний.Материал и методы. Изучена распространенность аллелей и генотипов rs4244285 в гене CYP2C19 в двух группах больных с коморбидными состояниями: ишемическая болезнь сердца с артериальной гипертензией (ИБС_АГ, n = 133); бронхиальная астма с гипертензией (БА_АГ, n = 178), в группе с изолированной патологией (БА, n = 135) и в популяционной выборке ...

Цель: изучение молекулярных механизмов развития заболеваний группы больших акушерских синдромов (БАС) на уровне транскриптома материнской части плаценты человека.Материал и методы. С помощью базы данных Gene Expression Omnibus (GEO) был осуществлен поиск результатов полногеномного профилирования плацентарной ткани человека для следующих фенотипов: физиологическая беременность, преэклампсия (ПЭ), невынашивание беременности и задержка роста плода (ЗРП). Было отобрано 11 наборов данных, которые были дополнены результатами собственного исследования, суммарно в интегративный анализ был включен 481 образец плацентарной ткани человека. Биоинформатическая обработка и статистический анализ данных были выполнены в программной среде R 3.6.1 с использованием пакетов Bioconductor. Итоговые наборы данных, объединенные по трем патологиям беременности, были использованы для поиска общих молекулярных мишеней БАС посредством анализа взвешенных сетей коэкспрессии генов (WGCNA). Функциональную аннотацию генов и полученных кластеров осуществляли в базе данных DAVID, сеть белок-белковых взаимодействий продуктов генов была построена с использованием программного обеспечения STRING, центральные гены для сети были идентифицированы с помощью анализа MCC плагина сytoHubba программного обеспечения Cytoscape 3.7.2.Результаты...

В представленной работе обобщены данные современных исследований, связанных с поиском генетической компоненты широко распространенных социально значимых заболеваний, которые приводят к нарушениям когнитивных функций человека. Основное внимание уделено таким патологиям многофакторной природы, как шизофрения (ШЗ) и болезнь Альцгеймера (БА). В статье приводится подробный анализ широкого спектра методов современной генетики: от близнецовых до эпигенетических исследований.