A case report of Pallister-Killian syndrome with an unusual mosaic supernumerary marker chromosome 12 with interstitial 12p13.1-p12.1 duplication.

Pallister-Killian syndrome (PKS) is a rare inherited disease with multiple congenital anomalies, profound intellectual disability, and the presence in the karyotype of sSMC - i(12)(p10). The frequency of PKS may be underestimated due to problems with cytogenetic diagnosis caused by tissue-specific mosaicism and usually a low percentage of peripheral blood cells containing sSMC. Such tissue-specific mosaicism also complicates a detailed analysis of the sSMC, which, along with the assessment of mosaicism in different tissues, is an important part of cytogenetic diagnosis in PKS. Unfortunately, a full-fledged diagnosis in PKS is either practically impossible or complicated. On the one hand, this is due to problems with the biopsy of various tissues (skin biopsy with fibroblast culture is most often used in practice); on the other - a low percentage of dividing peripheral blood cells containing sSMC, which often significantly complicates the analysis of its composition and organization. In the present study, a detailed analysis of sSMC was carried out in a patient with a characteristic clinical picture of PKS. A relatively high percentage of peripheral blood cells with sSMC (50%) made it possible to perform a detailed molecular cytogenetic analysis of de novo sSMC using chromosomal in situ suppression hybridization (CISS-hybridization), multicolor FISH (mFISH), multicolor chromosome banding (MCB), array CGH (aCGH), and quantitative real-time PCR (qPCR), and short tandem repeat (STR) - analysis. As a result, it was found that the sSMC is not a typical PKS derivative of chromosome 12. In contrast to the classical i(12)(p10) for PKS, the patient's cells contained an acrocentric chromosome consisting of 12p material. Clusters of telomeric repeats were found at the both ends of the sSMC. Furthemore, the results of aCGH and qPCR indicate the presence of interstitial 8.9 Mb duplication at 12p13.1-p12.1 within the sSMC, which leads to different representations of DNA from different segments of 12p within cells containing sSMC. The obtained data raise the question of the instability of the sSMC and, as a consequence, the possible presence of additional rearrangements, which, in traditional cytogenetic analysis of patients with PKS, are usually described as i(12)(p10).

Analysis of mutations spectrum in the ATP7B gene in patients with Wilson disease using massively parallel sequencing.

The study aimed to search for mutations in the ATP7B gene using massively parallel sequencing in patients with Wilson disease in the Tomsk region. For 42 patients with suspected Wilson's disease (aged from 1 to 33 years) was performed molecular genetic analysis. Enrichment of the interest genome regions was carried out by the long-range PCR. DNA libraries with ligated adapters were constructed with Nextera DNA Flex (Illumina, USA) kit. Sequencing was performed on the Illumina MiSeq platform (Illumina, USA). As a result of this work, we identified 9 pathogenic genetic variants. All variants were previously described in the literature and were found in patients with Wilson's disease. Five missense mutations, one splice site mutation, and 3 frameshift mutations were identified. In patients with Wilson's disease in the Tomsk region, the most common variant was c.3207C>A, this variant is the most common both in the Russian Federation and in other European populations. Also, a pathogenic variant c.3036dupC was found, which is probably endemic to the Russian Federation.

Generation of an induced pluripotent stem cell line ICGi030-A from a Wilson's disease patient carrying a frameshift mutation p.Lys1013fs and missense mutation p.H1069Q in the ATP7B gene.

Wilson's disease is a rare autosomal recessive disorder of copper metabolism. The copper accumulation in the viscera appears due to the functional impairment of copper-transporting ATPase, which is encoded by the ATP7B gene. In this study, PBMCs of a patient with two ATP7B mutations were reprogrammed. The first mutation is a missense mutation p.H1069Q, which is the most frequent mutation in the human population. At the same time, the second one is a frameshift mutation p.Lys1013fs. The generated iPSC line had a normal karyotype, maintained the original genotype, expressed pluripotency markers, and demonstrated the ability to differentiate into derivatives of the three germ layers.

Generation of two induced pluripotent stem cell lines from peripheral blood mononuclear cells of a patient with Wilson's disease.

Wilson's disease is an inherited disorder associated with copper accumulation in the liver, brain and other vital organs. Wilson's disease is caused by mutations in the ATP7B gene. Over 300 mutations of ATP7B have been described. Despite the disease is autosomal recessive, the patient whose PBMCs were reprogrammed in the study harbours heterozygous mutation c.3207C > A (p.H1069Q). Detailed analysis of the ATP7B complete gene sequencing data has not revealed other known disease associated mutation. The generated iPSC lines maintained the original genotype, expressed pluripotency markers, had normal karyotype and demonstrated the ability to differentiate into derivatives of the three germ layers.

Generation of four iPSC lines from two siblings with a microdeletion at the CNTN6 gene and intellectual disability.

The human induced pluripotent stem cell (iPSC) lines, ICGi009-A, ICGi009-B, ICGi013-A and ICGi013-B, were generated from skin fibroblasts of two siblings with intellectual disability. Both patients were carriers of CNTN6 gene microdeletion (Kashevarova et al., 2014). iPSC lines have normal karyotype, express pluripotency markers, are able to differentiate in vitro into derivatives of all three germ layers and represent a unique tool to study neurodevelopmental disorders.

Induced pluripotent stem cell line, ICAGi001-A, derived from human skin fibroblasts of a patient with 2p25.3 deletion and 2p25.3-p23.3 inverted duplication.

Skin fibroblasts from a patient with developmental delay and chromosome 2p25.3 deletion syndrome were reprogrammed into induced pluripotent stem cells (iPSCs) and the clonal stem cell line ICAGi001-A (iTAF9-11) was established. ICAGi001-A pluripotency was demonstrated in vitro by three germ layer differentiation capacity. This line is a good model for studying of the developmental delay and brain disorder.

[Preimplantation Genetic Diagnosis by Blastocentesis: Problems and Perspectives].

The discovery of cell-free DNA in blastocoele fluid opens new perspectives for the development of preimplantation genetic diagnosis of human chromosomal and genetic diseases. In this review we analyzed the results of the first studies, which made it possible to evaluate the effectiveness of the application of a new source of biological material and showed a high degree of agreement between the results of molecular karyotyping with cell-free DNA and blastocyst cells. The results suggest the possibility of developing a noninvasive method of preimplantation genetic diagnosis, which may open a new round of progress in the field of assisted reproductive technologies and the genetics of early stages of human ontogenesis.

MOLECULAR KARYOTYPING BY USING CELL-FREE DNA FROM HUMAN BLASTOCOELE FLUID, EMBRYOBLAST AND TROPHOBLAST CELLS.

In the present study, we have carried out a comparative analysis of molecular karyotypes of cell free DNA from blastocoele fluid, trophectoderm and inner cell mass of human blastocysts at the preimplantation stages of development, using the comparative genomic hybridization. Different types of chromosomal abnormalities distribution between trophectoderm, inner cell mass and blastocoele fluid were identified. It was first shown that the source of cell free DNA in the blastocoele fluid may arise from the cells of inner cell mass in addition to the trophectoderm cells, which are traditionally used in preimplantation genetic diagnosis of chromosomal aberrations. These results support the promising of blastocentesis as a new technology of preimplantation genetic diagnosis, which provides the possibility of integral analysis of chromosome abnormalities in different cells of the blastocyst.

[Molecular Karyotyping of Cell-Free DNA from Blastocoele Fluid as a Basis for Noninvasive Preimplantation Genetic Screening of Aneuploidy].

The discovery of DNA fragments in the blastocoele fluid is promising for the development of new noninvasive methods for the preimplantation genetic diagnosis of chromosomal diseases. However, to date there are no data confirming the concordance between the molecular karyotype of cell-free DNA from blastocoele fluid and the blastocyst cells per se. This paper reports on this concordance according to the results of molecular-cytogenetic analysis of the chromosomal set with the use of comparative genomic hybridization.

[Clinical and genetic analysis of idiopathic intellectual disability based on array comparative genomic hybridization].

In this study authors searched for chromosomal aberrations in 71 children with developmental delay or idiopathic mental retardation using Human Genome CGH Microarray Kits 4×44K and 8×60K (Agilent Technologies, USA). Microdeletions and microduplications, as well as CNV, which may be related to intellectual disability and associated with regions of known hereditary diseases or chromosomal syndromes were identified in 14 (20%) children (these patients are described in this article). During the analysis, candidate genes localized within the regions of aberrations and associated with development and functioning of nervous system were denoted.