Publications by authors named "Nikolay A Skryabin"

16 Publications

  • Page 1 of 1

Differential DNA Methylation of the IMMP2L Gene in Families with Maternally Inherited 7q31.1 Microdeletions is Associated with Intellectual Disability and Developmental Delay.

Cytogenet Genome Res 2021 Apr 13:1-15. Epub 2021 Apr 13.

Research Institute of Medical Genetics, Tomsk National Research Medical Center, Tomsk, Russian Federation.

Most copy number variations (CNVs) in the human genome display incomplete penetrance with unknown underlying mechanisms. One such mechanism may be epigenetic modification, particularly DNA methylation. The IMMP2L gene is located in a critical region for autism susceptibility on chromosome 7q (AUTS1). The level of DNA methylation was assessed by bisulfite sequencing of 87 CpG sites in the IMMP2L gene in 3 families with maternally inherited 7q31.1 microdeletions affecting the IMMP2L gene alone. Bisulfite sequencing revealed comparable levels of DNA methylation in the probands, healthy siblings without microdeletions, and their fathers. In contrast, a reduced DNA methylation index and increased IMMP2L expression were observed in lymphocytes from the healthy mothers compared with the probands. A number of genes were upregulated in the healthy mothers compared to controls and downregulated in probands compared to mothers. These genes were enriched in components of the ribosome and electron transport chain, as well as oxidative phosphorylation and various degenerative conditions. Differential expression in probands and mothers with IMMP2L deletions relative to controls may be due to compensatory processes in healthy mothers with IMMP2L deletions and disturbances of these processes in probands with intellectual disability. The results suggest a possible partial compensation for IMMP2L gene haploinsufficiency in healthy mothers with the 7q31.1 microdeletion by reducing the DNA methylation level. Differential DNA methylation of intragenic CpG sites may affect the phenotypic manifestation of CNVs and explain the incomplete penetrance of chromosomal microdeletions.
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http://dx.doi.org/10.1159/000514491DOI Listing
April 2021

46,XY,r(8)/45,XY,-8 Mosaicism as a Possible Mechanism of the Imprinted Birk-Barel Syndrome: A Case Study.

Genes (Basel) 2020 Dec 9;11(12). Epub 2020 Dec 9.

Research Institute of Medical Genetics, Tomsk National Research Medical Center (NRMC), Ushaika Street 10, 634050 Tomsk, Russia.

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 gene, which is expressed from the maternal allele. Heterozygous 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 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 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.
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http://dx.doi.org/10.3390/genes11121473DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7763634PMC
December 2020

Delineation of Clinical Manifestations of the Inherited Xq24 Microdeletion Segregating with sXCI in Mothers: Two Novel Cases with Distinct Phenotypes Ranging from UBE2A Deficiency Syndrome to Recurrent Pregnancy Loss.

Cytogenet Genome Res 2020 30;160(5):245-254. Epub 2020 May 30.

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.
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http://dx.doi.org/10.1159/000508050DOI Listing
September 2020

Gene Expression Profiling Revealed 2 Types of Bronchial Basal Cell Hyperplasia and Squamous Metaplasia With Different Progression Potentials.

Appl Immunohistochem Mol Morphol 2020 07;28(6):477-483

Tomsk National Research Medical Center.

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.
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http://dx.doi.org/10.1097/PAI.0000000000000762DOI Listing
July 2020

A mosaic intragenic microduplication of LAMA1 and a constitutional 18p11.32 microduplication in a patient with keratosis pilaris and intellectual disability.

Am J Med Genet A 2018 11 23;176(11):2395-2403. Epub 2018 Sep 23.

Laboratory of Cytogenetics, Research Institute of Medical Genetics, Tomsk NRMC, Tomsk, Russia.

The application of array-based comparative genomic hybridization and next-generation sequencing has identified many chromosomal microdeletions and microduplications in patients with different pathological phenotypes. Different copy number variations are described within the short arm of chromosome 18 in patients with skin diseases. In particular, full or partial monosomy 18p has also been associated with keratosis pilaris. Here, for the first time, we report a young male patient with intellectual disability, diabetes mellitus (type I), and keratosis pilaris, who exhibited a de novo 45-kb microduplication of exons 4-22 of LAMA1, located at 18p11.31, and a 432-kb 18p11.32 microduplication of paternal origin containing the genes METTL4, NDC80, and CBX3P2 and exons 1-15 of the SMCHD1 gene. The microduplication of LAMA1 was identified in skin fibroblasts but not in lymphocytes, whereas the larger microduplication was present in both tissues. We propose LAMA1 as a novel candidate gene for keratosis pilaris. Although inherited from a healthy father, the 18p11.32 microduplication, which included relevant genes, could also contribute to phenotype manifestation.
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http://dx.doi.org/10.1002/ajmg.a.40478DOI Listing
November 2018

Karyotype of the blastocoel fluid demonstrates low concordance with both trophectoderm and inner cell mass.

Fertil Steril 2018 06;109(6):1127-1134.e1

Cytogenetics Laboratory, Research Institute of Medical Genetics, Tomsk National Research Medical Center of Russian Academy of Sciences, Tomsk, Russian Federation; Department of Medical Genetics, Siberian State Medical University, Tomsk, Russian Federation.

Objective: To compare the genomic profiles of blastocoel fluid (BF), inner cell mass (ICM), and trophectoderm (TE) cells derived from the same blastocyst.

Design: Prospective study.

Setting: Academic and in vitro fertilization units.

Patient(s): Sixteen donated cryopreserved embryos at blastocyst stage.

Intervention(s): BF, TE, and ICM cells were retrieved from each blastocyst for chromosome analysis by means of next-generation sequencing (NGS).

Main Outcome Measure(s): Aneuploidy screening and assessment of mosaicism in BF, TE and ICM samples with subsequent comparison of genomic profiles between the three blastocyst compartments.

Result(s): Out of 16 blastocysts, 10 BF samples and 14 TE and ICM samples provided reliable NGS data for comprehensive chromosome analysis. Only 40.0% of BF-DNA karyotypes were fully concordant with TE or ICM, compared with 85.7% concordance between TE and ICM. In addition, BF-DNA was burdened with mosaic aneuploidies and the total number of affected chromosomes in BF was significantly higher compared with the TE and ICM.

Conclusion(s): BF-DNA can be successfully amplified and subjected to NGS, but owing to increased discordance with ICM and TE, BF does not adequately represent the status of the rest of the embryo. To overcome biologic and technical challenges associated with BF sampling and processing, blastocentesis would require improvement in both laboratory protocols and aneuploidy calling algorithms. Therefore, TE biopsy remains the most effective way to predict embryonic karyotype, and the use of BF as a single source of DNA for preimplantation genetic screening is not yet advised.
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http://dx.doi.org/10.1016/j.fertnstert.2018.02.008DOI Listing
June 2018

Compound phenotype in a girl with r(22), concomitant microdeletion 22q13.32-q13.33 and mosaic monosomy 22.

Mol Cytogenet 2018 27;11:26. Epub 2018 Apr 27.

1Research Institute of Medical Genetics, Tomsk NRMC, Tomsk, Russia.

Background: Ring chromosome instability may influence a patient's phenotype and challenge its interpretation.

Results: Here, we report a 4-year-old girl with a compound phenotype. Cytogenetic analysis revealed her karyotype to be 46,XX,r(22). aCGH identified a 180 kb 22q13.32 duplication, a 2.024 Mb subtelomeric 22q13.32-q13.33 deletion, which is associated with Phelan-McDermid syndrome, and a maternal single gene 382-kb deletion of uncertain clinical significance located in the region of the 3q13.31 deletion syndrome. All chromosomal aberrations were confirmed by real-time PCR in lymphocytes and detected in skin fibroblasts. The deletions were also found in the buccal epithelium. According to FISH analysis, 8% and 24% of the patient's lymphocytes and skin fibroblasts, respectively, had monosomy 22.

Conclusions: We believe that a combination of 22q13.32-q13.33 deletion and monosomy 22 in a portion of cells can better define the clinical phenotype of the patient. Importantly, the presence of monosomic cells indicates ring chromosome instability, which may favor karyotype correction that is significant for the development of chromosomal therapy protocols.
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http://dx.doi.org/10.1186/s13039-018-0375-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5923029PMC
April 2018

Allele-Specific Biased Expression of the CNTN6 Gene in iPS Cell-Derived Neurons from a Patient with Intellectual Disability and 3p26.3 Microduplication Involving the CNTN6 Gene.

Mol Neurobiol 2018 Aug 11;55(8):6533-6546. Epub 2018 Jan 11.

Institute of Cytology and Genetics SB RAS, Novosibirsk, 630090, Russia.

Copy number variations (CNVs) of the human CNTN6 gene caused by megabase-scale microdeletions or microduplications in the 3p26.3 region are often the cause of neurodevelopmental disorders, including intellectual disability and developmental delay. Surprisingly, patients with different copy numbers of this gene display notable overlapping of neuropsychiatric symptoms. The complexity of the study of human neuropathologies is associated with the inaccessibility of brain material. This problem can be overcome through the use of reprogramming technologies that permit the generation of induced pluripotent stem (iPS) cells from fibroblasts and their subsequent in vitro differentiation into neurons. We obtained a set of iPS cell lines derived from a patient carrier of the CNTN6 gene duplication and from two healthy donors. All iPS cell lines displayed the characteristics of pluripotent cells. Some iPS cell lines derived from the patient and from healthy donors were differentiated in vitro by exogenous expression of the Ngn2 transcription factor or by spontaneous neural differentiation of iPS cells through the neural rosette stage. The obtained neurons showed the characteristics of mature neurons as judged by the presence of neuronal markers and by their electrophysiological characteristics. Analysis of allele-specific expression of the CNTN6 gene in these neuronal cells by droplet digital PCR demonstrated that the level of expression of the duplicated allele was significantly reduced compared to that of the wild-type allele. Importantly, according to the sequencing data, both copies of the CNTN6 gene, which were approximately 1 Mb in size, showed no any additional structural rearrangements.
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http://dx.doi.org/10.1007/s12035-017-0851-5DOI Listing
August 2018

Clinically relevant morphological structures in breast cancer represent transcriptionally distinct tumor cell populations with varied degrees of epithelial-mesenchymal transition and CD44CD24 stemness.

Oncotarget 2017 Sep 19;8(37):61163-61180. Epub 2017 May 19.

Department of General and Molecular Pathology, Cancer Research Institute, Tomsk National Research Medical Center, Russian Academy of Sciences, 634050, Tomsk, Russian Federation.

Intratumor morphological heterogeneity in breast cancer is represented by different morphological structures (tubular, alveolar, solid, trabecular, and discrete) and contributes to poor prognosis; however, the mechanisms involved remain unclear. In this study, we performed 3D imaging, laser microdissection-assisted array comparative genomic hybridization and gene expression microarray analysis of different morphological structures and examined their association with the standard immunohistochemistry scorings and CD44CD24 cancer stem cells. We found that the intratumor morphological heterogeneity is not associated with chromosomal aberrations. By contrast, morphological structures were characterized by specific gene expression profiles and signaling pathways and significantly differed in progesterone receptor and Ki-67 expression. Most importantly, we observed significant differences between structures in the number of expressed genes of the epithelial and mesenchymal phenotypes and the association with cancer invasion pathways. Tubular (tube-shaped) and alveolar (spheroid-shaped) structures were transcriptionally similar and demonstrated co-expression of epithelial and mesenchymal markers. Solid (large shapeless) structures retained epithelial features but demonstrated an increase in mesenchymal traits and collective cell migration hallmarks. Mesenchymal genes and cancer invasion pathways, as well as Ki-67 expression, were enriched in trabecular (one/two rows of tumor cells) and discrete groups (single cells and/or arrangements of 2-5 cells). Surprisingly, the number of CD44CD24 cells was found to be the lowest in discrete groups and the highest in alveolar and solid structures. Overall, our findings indicate the association of intratumor morphological heterogeneity in breast cancer with the epithelial-mesenchymal transition and CD44CD24 stemness and the appeal of this heterogeneity as a model for the study of cancer invasion.
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http://dx.doi.org/10.18632/oncotarget.18022DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5617414PMC
September 2017

Genomic structural variations for cardiovascular and metabolic comorbidity.

Sci Rep 2017 01 25;7:41268. Epub 2017 Jan 25.

Laboratory of Population Genetics, Research Institute of Medical Genetics, Tomsk National Research Medical Center, Russian Academy of Sciences, Tomsk, Russia.

The objective of this study was to identify genes targeted by both copy number and copy-neutral changes in the right coronary arteries in the area of advanced atherosclerotic plaques and intact internal mammary arteries derived from the same individuals with comorbid coronary artery disease and metabolic syndrome. The artery samples from 10 patients were screened for genomic imbalances using array comparative genomic hybridization. Ninety high-confidence, identical copy number variations (CNVs) were detected. We also identified eight copy-neutral changes (cn-LOHs) > 1.5 Mb in paired arterial samples in 4 of 10 individuals. The frequencies of the two gains located in the 10q24.31 (ERLIN1) and 12q24.11 (UNG, ACACB) genomic regions were evaluated in 33 paired arteries and blood samples. Two patients contained the gain in 10q24.31 (ERLIN1) and one patient contained the gain in 12q24.11 (UNG, ACACB) that affected only the blood DNA. An additional two patients harboured these CNVs in both the arteries and blood. In conclusion, we discovered and confirmed a gain of the 10q24.31 (ERLIN1) and 12q24.11 (UNG, ACACB) genomic regions in patients with coronary artery disease and metabolic comorbidity. Analysis of DNA extracted from blood indicated a possible somatic origin for these CNVs.
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http://dx.doi.org/10.1038/srep41268DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5264603PMC
January 2017

A de novo microtriplication at 4q21.21-q21.22 in a patient with a vascular malignant hemangioma, elongated sigmoid colon, developmental delay, and absence of speech.

Am J Med Genet A 2016 08 10;170(8):2089-96. Epub 2016 Jun 10.

Institute of Medical Genetics, Tomsk, Russia.

The widespread application of array comparative genomic hybridization (aCGH) has provided new insights into the clinical significance of copy number variations (CNVs) in the human genome. Many microdeletion syndromes have recently been linked to corresponding reciprocal microduplication syndromes related to CNVs in the same chromosomal regions. However, the extent of CNVs may not be restricted to only microduplications but may also include microtriplications or even quadruplications. 4q21 microdeletion syndrome is one of these recently described syndromes. The phenotype includes growth restriction, neonatal hypotonia, severe developmental delay, absent or delayed speech, and distinct facial features. The minimal critical deleted region, which is 1.3 Mb in size, contains the PRKG2, RASGEF1B, HNRNPD, HNRPDL, and ENOPH1 genes. Here, we report a 5.4-year-old girl with developmental delay, absence of speech, muscular hypertension, macrocephaly, a broad forehead, frontal bossing, relatively elongated extremities, a vascular malignant hemangioma in anamnesis, and elongated sigmoid colon. aCGH revealed a microtriplication at 4q21.21-q21.22 that was 1.61 Mb in size. This de novo microtriplication included nine genes (BMP3, PRKG2, RASGEF1B, HNRNPD, HNRPDL, ENOPH1, TMEM150C, LINC00575, and SCD5) and overlapped with the minimal critical region for 4q21 microdeletion syndrome. Some clinical features of the patient were similar to those of 4q21 microdeletion (macrocephaly, frontal bossing, developmental delay, absence of speech, and anxiety), whereas others were mirrored (elongated extremities and muscular hypertension). The first identified case of a de novo microtriplication at 4q21.21-q21.22 emphasizes the clinical significance of CNVs at 4q21 for patients with developmental delay and absence of speech. © 2016 Wiley Periodicals, Inc.
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http://dx.doi.org/10.1002/ajmg.a.37754DOI Listing
August 2016

Comparative Cytogenetic Analysis of Spontaneous Abortions in Recurrent and Sporadic Pregnancy Losses.

Biomed Hub 2016 Jan-Apr;1(1):1-11. Epub 2016 Apr 27.

Laboratory of Cytogenetics, Institute of Medical Genetics, Siberian State Medical University, Tomsk, Russia.

Background: The majority of miscarriages are sporadic; however, 1-5% of couples experience recurrent pregnancy loss (RPL). Approximately 50-60% of miscarriages result from chromosomal abnormalities. Currently, there are conflicting reports regarding the rates of chromosomal abnormalities between recurrent and sporadic pregnancy losses.

Methods: A retrospective comparative cytogenetic analysis of 442 RPL and 466 sporadic abortions (SA) was performed. Maternal age and medical background were evaluated, and chromosomal abnormality rates were compared between groups.

Results: The frequency of embryos with abnormal karyotypes was significantly higher in SA compared to RPL (56.7 and 46.6%, respectively), and abortions from women under 30 years of age were the main contributor to this difference. An age-dependent increase in the abnormal karyotype rate was observed in two groups of women - those with SA [53.0 and 70.1% for younger and older (≥35-year-old) mothers, respectively] and those with idiopathic RPL without any concomitant reproductive pathology (46.5 and 78.4% for younger and older mothers) - but not in the group of women with RPL associated with concomitant reproductive pathology. The incidence of recurrent abnormal karyotypes in subsequent miscarriages was significantly higher than random probability (odds ratio = 22.75).

Conclusion: Our findings highlight the variability in the risk of aneuploidy in recurrent abortion.
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http://dx.doi.org/10.1159/000446099DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6945958PMC
April 2016

Relationship between morphological and cytogenetic heterogeneity in invasive micropapillary carcinoma of the breast: a report of one case.

J Clin Pathol 2015 Sep 15;68(9):758-62. Epub 2015 Jun 15.

Department of Pathological Anatomy and Cytology, Tomsk Cancer Research Institute, Tomsk, Russian Federation Department of Pathological Anatomy, Siberian State Medical University, Tomsk, Russian Federation.

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http://dx.doi.org/10.1136/jclinpath-2015-203009DOI Listing
September 2015

Single gene microdeletions and microduplication of 3p26.3 in three unrelated families: CNTN6 as a new candidate gene for intellectual disability.

Mol Cytogenet 2014 31;7(1):97. Epub 2014 Dec 31.

Laboratory of Cytogenetics, Institute of Medical Genetics, 10 Nab. Ushaiki, 634050 Tomsk, Russia ; Department of Medical Genetics, Siberian State Medical University, Tomsk, Russia.

Background: Detection of submicroscopic chromosomal alterations in patients with a idiopathic intellectual disability (ID) allows significant improvement in delineation of the regions of the genome that are associated with brain development and function. However, these chromosomal regions usually contain several protein-coding genes and regulatory elements, complicating the understanding of genotype-phenotype correlations. We report two siblings with ID and an unrelated patient with atypical autism who had 3p26.3 microdeletions and one intellectually disabled patient with a 3p26.3 microduplication encompassing only the CNTN6 gene.

Results: Two 295.1-kb microdeletions and one 766.1-kb microduplication of 3p26.3 involving a single gene, CNTN6, were identified with an Agilent 60K array. Another 271.9-kb microdeletion of 3p26.3 was detected using an Affymetrix CytoScan HD chromosome microarray platform. The CHL1 and CNTN4 genes, although adjacent to the CNTN6 gene, were not affected in either of these patients.

Conclusions: The protein encoded by CNTN6 is a member of the immunoglobulin superfamily and functions as a cell adhesion molecule that is involved in the formation of axon connections in the developing nervous system. Our results indicate that CNTN6 may be a candidate gene for ID.
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http://dx.doi.org/10.1186/s13039-014-0097-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4299808PMC
January 2015

Array CGH analysis of a cohort of Russian patients with intellectual disability.

Gene 2014 Feb 27;536(1):145-50. Epub 2013 Nov 27.

Institute of Medical Genetics, Tomsk, Russia.

The use of array comparative genomic hybridization (array CGH) as a diagnostic tool in molecular genetics has facilitated the identification of many new microdeletion/microduplication syndromes (MMSs). Furthermore, this method has allowed for the identification of copy number variations (CNVs) whose pathogenic role has yet to be uncovered. Here, we report on our application of array CGH for the identification of pathogenic CNVs in 79 Russian children with intellectual disability (ID). Twenty-six pathogenic or likely pathogenic changes in copy number were detected in 22 patients (28%): 8 CNVs corresponded to known MMSs, and 17 were not associated with previously described syndromes. In this report, we describe our findings and comment on genes potentially associated with ID that are located within the CNV regions.
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http://dx.doi.org/10.1016/j.gene.2013.11.029DOI Listing
February 2014

Phenotypic drift as a cause for intratumoral morphological heterogeneity of invasive ductal breast carcinoma not otherwise specified.

Biores Open Access 2013 Apr;2(2):148-54

Department of Pathological Anatomy and Cytology, Cancer Research Institute, Siberian Branch of the Russian Academy of Medical Sciences , Tomsk, Russian Federation. ; Department of Pathological Anatomy, Siberian State Medical University , Tomsk, Russian Federation.

Invasive ductal carcinoma (IDC) not otherwise specified (NOS), the most common type of breast cancer, demonstrates great intratumoral morphological heterogeneity, which encompasses the presence of different types of morphological structures-tubular, trabecular, solid, and alveolar structures and discrete groups of tumor cells, the origins of which remain unclear at present. In this study of 162 IDC NOS patients, we investigated whether the distribution of different types of morphological structures is related to the basic clinicopathological parameters of IDC NOS. Our results showed that in patients with only one type of tumor structure, the presence of any one of the five types was equally probable; however, cases with two types of structures were more likely to contain trabecular structures than the other four types. The development of intratumoral morphological heterogeneity was not associated with menopausal status, tumor size, histological grade, hematogenic metastasis, or recurrence. However, the number of different types of morphological structures was significantly higher in luminal tumors than in triple-negative tumors. An increase in the frequency of lymph node metastasis correlated with the increased number of different types of structures in breast tumors; however, in contrast to premenopausal patients, this association was explained by the presence of alveolar structures in postmenopausal women. In addition, we showed a significant decrease in the numbers of positive lymph nodes in tumors with high numbers of morphological variants. The frequency of lymph node metastases and the number of positive nodes were generally independent features and formed by different mechanisms. Based on the evidence, the term "phenotypic drift" has been designated as the basis for the development of intratumoral morphological heterogeneity of IDC NOS.
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http://dx.doi.org/10.1089/biores.2012.0278DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3620470PMC
April 2013