Ring chromosome 8 (r(8)) is one of the least frequent ring chromosomes. Usually, maternal chromosome 8 forms a ring, which can be lost from cells due to mitotic instability. The 8q24 region contains the imprinted KCNK9 gene, which is expressed from the maternal allele. Heterozygous KCNK9 mutations are associated with the imprinting disorder Birk-Barel syndrome. Here, we report a 2.5-year-old boy with developmental delay, microcephaly, dysmorphic features, diffuse muscle hypotonia, feeding problems, motor alalia and noncoarse neurogenic type of disturbance of muscle electrogenesis, partially overlapping with Birk-Barel syndrome phenotype. Cytogenetic analysis of lymphocytes revealed his karyotype to be 46,XY,r(8)(p23q24.3)[27]/45,XY,-8[3]. A de novo 7.9 Mb terminal 8p23.3p23.1 deletion, a 27.1 Mb 8p23.1p11.22 duplication, and a 4.4 Mb intact segment with a normal copy number located between them, as well as a 154-kb maternal LINGO2 gene deletion (9p21.2) with unknown clinical significance were identified by aCGH + SNP array. These aberrations were confirmed by real-time PCR. According to FISH analysis, the 8p23.1-p11.22 duplication was inverted. The ring chromosome originated from maternal chromosome 8. Targeted massive parallel sequencing did not reveal the KCNK9 mutations associated with Birk-Barel syndrome. Our data allow to assume that autosomal monosomy with inactive allele of imprinted gene arising from the loss of a ring chromosome in some somatic cells may be an etiological mechanism of mosaic imprinting disorders, presumably with less severe phenotype.

Haplotype associations of 894 DNA samples of elderly people from the Russian population of Tomsk were analyzed using 49 SNPs (single nucleotide polymorphisms). As the analyzed markers, SNPs were selected that showed an association with Alzheimer’s disease or variability of cognitive abilities in genome-wide association studies. As a result of the analysis, blocks on chromosomes 1, 2, 6, 8, 11, 19, and 20 were identified. Significant associations were shown, taking into account 50000 permutations, for haplotypes localized on chromosomes 1 and 19 in the genes CR1 and APOE, APOC1, respectively. Our results confirm the role of the APOE and CR1 genes in the pathogenesis of Alzheimer’s disease in the Russian population.

Genome stability is an integral feature of all living organisms. Aneuploidy is the most common cause of fetal death in humans. The timing of bursts in increased aneuploidy frequency coincides with the waves of global epigenetic reprogramming in mammals. During gametogenesis and early embryogenesis, parental genomes undergo two waves of DNA methylation reprogramming. Failure of these processes can critically affect genome stability, including chromosome segregation during cell division. Abnormal methylation due to errors in the reprogramming process can potentially lead to aneuploidy. On the other hand, the presence of an entire additional chromosome, or chromosome loss, can affect the global genome methylation level. The associations of these two phenomena are well studied in the context of carcinogenesis, but here, we consider the relationship of DNA methylation and aneuploidy in early human and mammalian ontogenesis. In this review, we link these two phenomena and highlight the critical ontogenesis periods and genome regions that play a significant role in human reproduction and in the formation of pathological phenotypes in newborns with chromosomal aneuploidy.

Apathy is one of the most frequent, disabling and difficult to treat non-motor symptoms manifesting in many neurodegenerative diseases, particularly in Parkinson disease and Huntington disease. Aim is to evaluate and compare the clinical profile of apathy in patients with Parkinson disease (PD) and Huntington disease (HD). Materials and methods. The individual registration card was filled in for each patient containing demographic data, clinical features of the disease, the results of validated scales and questionnaires evaluating motor activity (The Movement Disorder Society-Unified Parkinson's Disease

Rating Scale – MDS-UPDRS, the Unified Huntington's Disease Rating Scale – UHDRS), cognitive functions (MoCA-test), anxiety-depressive symptoms (hospital scale for evaluating anxiety and depression, Beck's depression scale-II), apathy (apathy rating scale). Patients with dementia or severe depression were excluded from the study.

Results. The study included 265 patients: 250 with PD and 15 with HD. Apathy was diagnosed in 57.8% of cases in patients with neurodegenerative diseases (139 out of 250 patients with PD and 9 out of 15 patients with HD). In both groups of patients apathy was associated with the severity of motor manifestations. Patients with PD showed a positive correlation of apathy with more severe depression (r=0.488; p<0.0001), anxiety (r=0.300; p<0.0001) and drowsiness (r=0.254; p<0.0001); a negative correlation with a short duration of the disease (r=-0.160; p=0.021), a lower dose of dopaminergic drugs, LEDD (r=-0.203; p=0.03). In patients with HD, apathy was associated with disease duration (8 (4; 11) years in patients without apathy and 5 (3;9) years in patients with apathy, U =3791.5; p=0.020) and cognitive impairment (26 (19;37) points, without apathy – 18 (12;26), U =3548.5; p=0.003).

Conclusions. Similar frequency of apathy was found in patients with PD and HD, but with different clinical correlations due to the involvement of different brain regions in the pathological process, which requires further research to develop targeted therapy

Hyperprolactinaemia, a common adverse effect of antipsychotic drugs, is primarily linked to blockade of dopamine D2 receptors in the pituitary gland. Certain antipsychotic drugs, such as, for example risperidone and paliperidone, are more likely to induce hyperprolactinaemia compared to others. This effect is probably caused by a relatively high blood/brain concentration ratio, a consequence of being a substrate of P-glycoprotein. Genetic variants of P-glycoprotein with changed functional activity might influence the potential of risperidone and paliperidone to cause hyperprolactinaemia as the altered blood/brain concentration ratio would lead to a reduced therapeutic drug level within essential brain areas making dose adaptations necessary. This increases exposure of dopamine D2 receptors within the pituitary gland.

The World Health Organization (WHO) regards atherosclerosis-related myocardial infarction and stroke as the main causes of death in humans. Susceptibility to atherogenesis-associated diseases is caused by single-nucleotide polymorphisms (SNPs). (2) Methods: Using our previously developed public web-service SNP_TATA_Comparator, we estimated statistical significance of the SNP-caused alterations in TATA-binding protein (TBP) binding affinity for 70 bp proximal promoter regions of the human genes clinically associated with diseases syntonic or dystonic with atherogenesis. Additionally, we did the same for several genes related to the maintenance of mitochondrial genome integrity, according to present-day active research aimed at retarding atherogenesis. (3) Results: In dbSNP, we found 1186 SNPs altering such affinity to the same extent as clinical SNP markers do (as estimated). Particularly, clinical SNP marker rs2276109 can prevent autoimmune diseases via reduced TBP affinity for the human MMP12 gene promoter and therefore macrophage elastase deficiency, which is a well-known physiological marker of accelerated atherogenesis that could be retarded nutritionally using dairy fermented by lactobacilli. (4) Conclusions: Our results uncovered SNPs near clinical SNP markers as the basis of neutral drift accelerating atherogenesis and SNPs of genes encoding proteins related to mitochondrial genome integrity and microRNA genes associated with instability of the atherosclerotic plaque as a basis of directional natural selection slowing atherogenesis. Their sum may be stabilizing the natural selection that sets the normal level of atherogenesis.

Noninvasive prenatal testing (NIPT) using cell-free fetal DNA has increasingly been adopted as a screening tool for fetal aneuploidies. Several studies have discussed benefits and limitations of NIPT compared with both ultrasound and invasive procedures, but in spite of some shortcomings NIPT has become extensively used within the last 5 years. This study aims to describe the current use of NIPT in Europe, Australia and the USA.

Chromosomal microdeletion syndromes present with a wide spectrum of clinical phenotypes that depend on the size and gene content of the affected region. In a healthy carrier, epigenetic mechanisms may compensate for the same microdeletion, which may segregate through several generations without any clinical symptoms until the epigenetic modifications no longer function. We report 2 novel cases of Xq24 microdeletions inherited from mothers with extremely skewed X-chromosome inactivation (sXCI). The first case is a boy presenting with X-linked mental retardation, Nascimento type, due to a 168-kb Xq24 microdeletion involving 5 genes (CXorf56, UBE2A, NKRF, SEPT6, and MIR766) inherited from a healthy mother and grandmother with sXCI. In the second family, the presence of a 239-kb Xq24 microdeletion involving 3 additional genes (SLC25A43, SLC25A5-AS1, and SLC25A5) was detected in a woman with sXCI and a history of recurrent pregnancy loss with a maternal family history without reproductive wastages or products of conception. These cases provide evidence that women with an Xq24 microdeletion and sXCI may be at risk for having a child with intellectual disability or for experiencing a pregnancy loss due to the ontogenetic pleiotropy of a chromosomal microdeletion and its incomplete penetrance modified by sXCI.

In this study, the effect of the THBS1 gene knockout on the survival of human tumor cells, the frequency of spontaneous and radiation-induced micronuclei, and the expression profile of genes in the HeLa cell line was investigated. It was shown that the THBS1 gene knockout led to a decrease in the plating efficiency before and after irradiation (1.4-fold, p = 0.0002 and 1.7-fold, p = 0.00009, respectively) and an increase in the frequency of spontaneous and radiation-induced micronuclei (1.9-fold, p = 0.02 and 2.5-fold, p = 0.01, respectively). In addition, expression of genes involved in the DNA repair processes, apoptosis, and G2/M cell cycle checkpoint was changed after THBS1 knockout in comparison with the intact HeLa cell line. Thus, the THBS1 gene knockout leads to an increase in the radiosensitivity of the HeLa cell line. This indicates the possible role of the THBS1 gene in the regulation of a radiation-induced cellular response.

Ring chromosomes are structural aberrations commonly associated with disease phenotype. We consider necessary to create the iPSCs with a ring chromosome 8, which can be used for disease modeling and related research. The ICGi025-A iPSCs line was obtained by the reprogramming of the skin fibroblasts from a 1-year-old boy with 46,XY,r(8)/45,XY,-8 mosaicism, developmental delay, microcephaly, dysmorphic features, diffuse muscle hypotonia, moderate proximal muscle weakness, feeding problems, and motor alalia. The iPSCs had expression of the pluripotency-associated markers. In vitro differentiated cells expressed the markers of the cells of three germ layers. That data allowed us to conclude that ICGi025-A cells were pluripotent.

Detection of translocations in subtelomeric regions of chromosomes is a serious diagnostic problem, because they are difficult to determine by conventional cytogenetics with G banding. The aim of this work was the development of the technology of DNA probe synthesis for unique sequences of subtelomeric chromosome regions based on long-range PCR using the clinical case of determining the parental origin of unbalanced translocation between chromosomes 5 and 8. The unbalanced translocation der(5)t(5;8)(р15.33;q24.22) in a proband with physical, motor, intellectual, and speech development delay and in his sibling with speech and intellectual development delay as well, which was previously identified by array comparative genomic hybridization (aCGH), was confirmed by FISH. A balanced translocation 46,XX,t(5;8)(p15.33;q24.22) was detected in the mother’s karyotype using the created locus-specific DNA probe. This chromosome aberration was not detected by G banding of metaphase chromosomes. The father’s karyotype was normal according to FISH results. The method presented here makes it possible to create locus-specific DNA probes in a molecular cytogenetic laboratory using long-range PCR for the rapid diagnosis of cryptic chromosomal rearrangements.

Детекция хромосомных транслокаций в субтеломерных участках хромосом представляет собой серьезную диагностическую проблему, поскольку транслокации в этих регионах с участием фрагментов хромосом небольшой протяженности сложно обнаружить при проведении стандартного кариотипирования с помощью методов дифференциального окрашивания. В настоящей работе разработана технология получения ДНК-зонда на уникальные последовательности субтеломерных регионов хромосом на основе ПЦР длинных фрагментов на примере определения родительского происхождения несбалансированной транслокации между хромосомами 5 и 8. По результатам FISH-анализа у пробанда с задержкой физического, моторного, психического и речевого развития и у сибса с задержкой речевого и психического развития была подтверждена выявленная ранее методом хромосомного микроматричного анализа (aCGH) несбалансированная транслокация der(5)t(5;8)(р15.33;q24.22). Размер делетированного участка на хромосоме 5 составил 2.4 млн пн, а протяженность дупликации 8q24.22qter – 11.7 млн пн. С помощью синтезированного локус-специфичного ДНК-зонда в кариотипе матери была обнаружена сбалансированная транслокация 46,XX,t(5;8)(p15.33;q24.22), не выявленная при метафазном анализе G-окрашенных хромосом, при этом у отца сбалансированная транслокация была исключена. Представленный в исследовании метод позволяет на базе молекулярно-цитогенетической лаборатории синтезировать локус-специфичные ДНК-зонды с помощью ПЦР длинных фрагментов для оперативной диагностики криптических хромосомных перестроек.

The premalignant process preceding squamous cell lung cancer is not inevitable; it can stop at any of the bronchial lesions: basal cell hyperplasia (BCH), squamous metaplasia (SM), and dysplasia and then progress or regress. At present, the mechanisms underlying the progression of the bronchial lesions remain undefined. Previously, we hypothesized that bronchial lesions that presented individually or combined with each other in the bronchi of lung cancer patients mirror the different ""scenarios"" of the premalignant process: individual BCH-the stoppage at the stage of hyperplasia, BCH plus SM-the progression of hyperplasia to metaplasia, and SM plus dysplasia-the progression of metaplasia to dysplasia. In this study, we analyzed gene expression profiles of BCH, SM, and dysplasia depending on their cooccurrence in the bronchi of lung cancer patients. The immune response gene expression was found to be a key difference between the individual BCH and BCH combined with SM lesions and a potential mechanism that determines the progression of hyperplasia to metaplasia. Upregulation of the cell cycle and downregulation of the cilium assembly genes mainly distinguished SM that copresented with dysplasia from SM that copresented with BCH and is a probable mechanism of the progression of metaplasia to dysplasia. Dysplasia showed mainly overexpression of the cell division genes and underexpression of the inflammation genes. Thus, this study demonstrates the significant gene expression differences between the premalignant lesions depending on their cooccurrence in the bronchi and sheds light on the mechanisms of the precancerous process preceding squamous cell lung cancer.