A girl with Down syndrome and partial trisomy for 21pter-q22.13: A clue to narrow the Down syndrome critical region

2007 ◽  
Vol 146A (1) ◽  
pp. 124-127 ◽  
Author(s):  
Daisuke Sato ◽  
Hiroki Kawara ◽  
Osamu Shimokawa ◽  
Naoki Harada ◽  
Hidefumi Tonoki ◽  
...  
2019 ◽  
Vol 7 (8) ◽  
Author(s):  
Maria Chiara Pelleri ◽  
Elena Cicchini ◽  
Michael B. Petersen ◽  
Lisbeth Tranebjærg ◽  
Teresa Mattina ◽  
...  

2021 ◽  
Vol 12 ◽  
Author(s):  
Francesca Antonaros ◽  
Margherita Pitocco ◽  
Domenico Abete ◽  
Beatrice Vione ◽  
Allison Piovesan ◽  
...  

Down syndrome (DS) is caused by trisomy of chromosome 21 and it is the most common genetic cause of intellectual disability (ID) in humans. Subjects with DS show a typical phenotype marked by facial dysmorphisms and ID. Partial trisomy 21 (PT21) is a rare genotype characterized by the duplication of a delimited chromosome 21 (Hsa21) portion and it may or may not be associated with DS diagnosis. The highly restricted Down syndrome critical region (HR-DSCR) is a region of Hsa21 present in three copies in all individuals with PT21 and a diagnosis of DS. This region, located on distal 21q22.13, is 34 kbp long and does not include characterized genes. The HR-DSCR is annotated as an intergenic region between KCNJ6-201 transcript encoding for potassium inwardly rectifying channel subfamily J member 6 and DSCR4-201 transcript encoding Down syndrome critical region 4. Two transcripts recently identified by massive RNA-sequencing (RNA-Seq) and automatically annotated on Ensembl database reveal that the HR-DSCR seems to be partially crossed by KCNJ6-202 and DSCR4-202 isoforms. KCNJ6-202 shares the coding sequence with KCNJ6-201 which is involved in many physiological processes, including heart rate in cardiac cells and circuit activity in neuronal cells. DSCR4-202 transcript has the first two exons in common with DSCR4-201, the only experimentally verified gene uniquely present in Hominidae. In this study, we performed in silico and in vitro analyses of the HR-DSCR. Bioinformatic data, obtained using Sequence Read Archive (SRA) and SRA-BLAST software, were confirmed by Reverse Transcription-Polymerase Chain Reaction (RT-PCR) and Sanger sequencing on a panel of human tissues. Our data demonstrate that the HR-DSCR cannot be defined as an intergenic region. Further studies are needed to investigate the functional role of the new transcripts, likely involved in DS phenotypes.


2007 ◽  
Vol 120 (11) ◽  
pp. 1859-1867 ◽  
Author(s):  
G. Berto ◽  
P. Camera ◽  
C. Fusco ◽  
S. Imarisio ◽  
C. Ambrogio ◽  
...  

Gene ◽  
2006 ◽  
Vol 372 ◽  
pp. 128-136 ◽  
Author(s):  
Silvia Canaider ◽  
Federica Facchin ◽  
Cristiana Griffoni ◽  
Raffaella Casadei ◽  
Lorenza Vitale ◽  
...  

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 2204-2204
Author(s):  
Satu Kyttaelae ◽  
Ivonne Habermann ◽  
Martin Bornhaeuser ◽  
Gerhard Ehninger ◽  
Alexander Kiani

Abstract NFAT (Nuclear Factor of Activated T cells) is a family of calcium-induced, calcineurin-dependent transcription factors, well characterized as central regulators of inducible gene expression in T lymphocytes but now known to function also in several other cell types in various adaptation and differentiation processes. Activation of NFAT by the phosphatase calcineurin is counteracted by several inhibitory kinases and can be completely blocked by the immunosuppressant Cyclosporin A. The Down syndrome critical region 1 (DSCR1; also termed CSP1, MCIP1 or RCAN1) gene belongs to the calcipressin family of endogenous calcineurin inhibitors and is expressed in several isoforms, one of which (isoform C, coded by exons 4–7) has been described to be a transcriptional target for NFAT in striated muscle, endothelial, and neural cells. The DSCR1 gene is located within the Down syndrome critical region of human chromosome 21 and is, together with 200–300 other genes, overexpressed about 1.5-fold in patients with Down syndrome (DS). Previously, dysregulation of NFAT signaling by overexpression of DSCR1 has been implicated in causing various of the pathophysiological features observed in DS patients. Children with DS also suffer from an about 500-fold increased incidence of acute megakaryocytic leukemia; the respective roles of NFAT or DSCR1 in megakaryocytes of either normal individuals or those with DS, however, has not yet been established. Here we show that DSCR1 is upregulated during megakaryocytic differentiation in a lineage-specific manner, and in mature megakaryocytes is further strongly induced by calcineurin stimulation. DSCR1 expression in megakaryocytes is regulated by NFAT, since overexpression of NFATc2 enhances, while overexpression of the specific inhibitor of NFAT activation, VIVIT, suppresses expression of the gene. We further demonstrate that DSCR1 does not only represent an NFAT target in megakaryocytes, but itself acts an inhibitor of NFAT signaling in these cells. Overexpression of DSCR1 in CMK cells as well as in primary megakaryocytes by retroviral transduction profoundly suppressed ionomycin-induced dephosphorylation and nuclear translocation of NFATc2, as well as transactivation of an NFAT-dependent promoter construct. Finally, overexpression of DSCR1 in megakaryocytes markedly downregulated both the constitutive and induced expression of Fas Ligand, a pro-apoptotic gene recently established as a NFAT target in megakaryocytes. Together, these results suggest that DSCR1 acts as an NFAT-induced NFAT inhibitor in megakaryocytes and, when overexpressed, interferes with the expression of NFAT-dependent megakaryocytic genes.


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