scholarly journals A New Case of the Rare 10q22.3q23.2 Microdeletion Flanked by Low-Copy Repeats 3/4

2017 ◽  
Vol 8 (3) ◽  
pp. 161-167 ◽  
Author(s):  
Miriam Coelho Molck ◽  
Milena Simioni ◽  
Társis Paiva Vieira ◽  
Fabíola Paoli Monteiro ◽  
Vera L. Gil-da-Silva-Lopes
Keyword(s):  
Low Copy Repeats

scholarly journals Rearrangements of the Williams–Beuren syndrome locus: molecular basis and implications for speech and language development

2007 ◽  
Vol 9 (15) ◽  
pp. 1-16 ◽  
Author(s):  
Lucy R. Osborne ◽  
Carolyn B. Mervis
Keyword(s):  
Language Development ◽  
Language Impairment ◽  
Short Term Memory ◽  
Relative Strength ◽  
Genomic Rearrangements ◽  
Speech And Language ◽  
Human Speech ◽  
Hyperactivity Disorder ◽  
Low Copy Repeats ◽  
Speech And Language Development

AbstractThe Williams–Beuren syndrome (WBS) locus on human chromosome 7q11.23 is flanked by complex chromosome-specific low-copy repeats that mediate recurrent genomic rearrangements of the region. Common genomic rearrangements arise through unequal meiotic recombination and result in complex but distinct behavioural and cognitive phenotypes. Deletion of 7q11.23 results in WBS, which is characterised by mild to moderate intellectual disability or learning difficulties, with relative cognitive strengths in verbal short-term memory and in language and extreme weakness in visuospatial construction, as well as anxiety, attention-deficit hyperactivity disorder and overfriendliness. By contrast, duplication results in severely delayed speech and expressive language, with relative strength in visuospatial construction. Although deletion and duplication of the WBS region have very different effects, both cause forms of language impairment and suggest that dosage-sensitive genes within the region are important for the proper development of human speech and language. The spectrum and frequency of genomic rearrangements at 7q11.23 presents an exceptional opportunity to identify gene(s) directly involved in human speech and language development.

scholarly journals Two Functional Copies of the DGCR6 Gene Are Present on Human Chromosome 22q11 Due to a Duplication of an Ancestral Locus

2001 ◽  
Vol 11 (2) ◽  
pp. 208-217
Author(s):  
Lisa Edelmann ◽  
Pavel Stankiewicz ◽  
Elizabeth Spiteri ◽  
Raj K. Pandita ◽  
Lisa Shaffer ◽  
...  
Keyword(s):  
Sequence Similarity ◽  
Primate Species ◽  
Region Gene ◽  
Chromosome 22Q11 ◽  
Expression Studies ◽  
Low Copy Repeats ◽  
Duplicate Locus ◽  
Human Chromosome 22Q11 ◽  
Velo Cardio Facial Syndrome ◽  
Functional Copy

The DGCR6 (DiGeorge critical region) gene encodes a putative protein with sequence similarity to gonadal(gdl), a Drosophila melanogaster gene of unknown function. We mapped the DGCR6 gene to chromosome 22q11 within a low copy repeat, termed sc11.1a, and identified a second copy of the gene, DGCR6L, within the duplicate locus, termed sc11.1b. Both sc11.1 repeats are deleted in most persons with velo-cardio-facial syndrome/DiGeorge syndrome (VCFS/DGS), and they map immediately adjacent and internal to the low copy repeats, termed LCR22, that mediate the deletions associated with VCFS/DGS. We sequenced genomic clones from both loci and determined that the putative initiator methionine is located further upstream than originally described, but in a position similar to the mouse and chicken orthologs.DGCR6L encodes a highly homologous, functional copy ofDGCR6, with some base changes rendering amino acid differences. Expression studies of the two genes indicate that both genes are widely expressed in fetal and adult tissues. Evolutionary studies using FISH mapping in several different species of ape combined with sequence analysis of DGCR6 in a number of different primate species indicate that the duplication is at least 12 million years old and may date back to before the divergence of Catarrhines from Platyrrhines, 35 mya. These data suggest that there has been selective evolutionary pressure toward the functional maintenance of both paralogs. Interestingly, a full-length HERV-K provirus integrated into the sc11.1a locus after the divergence of chimpanzees and humans.

The donor chromosome breakpoint for a jumping translocation is associated with large low-copy repeats in 21q21.3

2003 ◽  
Vol 101 (2) ◽  
pp. 118-123 ◽  
Author(s):  
P. Stankiewicz ◽  
S.W. Cheung ◽  
C.J. Shaw ◽  
R. Saleki ◽  
K. Szigeti ◽  
...  
Keyword(s):  
Low Copy Repeats ◽  
Donor Chromosome ◽  
Chromosome Breakpoint

scholarly journals Formation of a Family of Long Intergenic Noncoding RNA Genes with an Embedded Translocation Breakpoint Motif in Human Chromosomal Low Copy Repeats of 22q11.2—Some Surprises and Questions

2018 ◽  
Vol 4 (3) ◽  
pp. 16 ◽  
Author(s):  
Nicholas Delihas
Keyword(s):  
Noncoding Rna ◽  
Gene Sequence ◽  
Translocation Breakpoint ◽  
Segmental Duplications ◽  
New Genes ◽  
Genetic Abnormalities ◽  
Low Copy Repeats ◽  
Long Intergenic Noncoding Rna ◽  
And Function ◽  
Rna Genes

A family of long intergenic noncoding RNA (lincRNA) genes, FAM230 is formed via gene sequence duplication, specifically in human chromosomal low copy repeats (LCR) or segmental duplications. This is the first group of lincRNA genes known to be formed by segmental duplications and is consistent with current views of evolution and the creation of new genes via DNA low copy repeats. It appears to be an efficient way to form multiple lincRNA genes. But as these genes are in a critical chromosomal region with respect to the incidence of abnormal translocations and resulting genetic abnormalities, the 22q11.2 region, and also carry a translocation breakpoint motif, several intriguing questions arise concerning the presence and function of the translocation breakpoint sequence in RNA genes situated in LCR22s.

Two classes of low-copy repeats comediate a new recurrent rearrangement consisting of duplication at 8p23.1 and triplication at 8p23.2

2007 ◽  
Vol 28 (5) ◽  
pp. 459-468 ◽  
Author(s):  
Roberto Giorda ◽  
Roberto Ciccone ◽  
Giorgio Gimelli ◽  
Tiziano Pramparo ◽  
Silvana Beri ◽  
...  
Keyword(s):  
Low Copy Repeats

scholarly journals Recurrent deletions and reciprocal duplications of 10q11.21q11.23 including CHAT and SLC18A3 are likely mediated by complex low-copy repeats

2011 ◽  
Vol 33 (1) ◽  
pp. 165-179 ◽  
Author(s):  
Paweł Stankiewicz ◽  
Shashikant Kulkarni ◽  
Avinash V. Dharmadhikari ◽  
Srirangan Sampath ◽  
Samarth S. Bhatt ◽  
...  
Keyword(s):  
Low Copy Repeats

scholarly journals A Case of 17q21.31 Microduplication and 7q31.33 Microdeletion, Associated with Developmental Delay, Microcephaly, and Mild Dysmorphic Features

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Adrian Mc Cormack ◽  
Juliet Taylor ◽  
Leah Te Weehi ◽  
Donald R. Love ◽  
Alice M. George
Keyword(s):  
Homologous Recombination ◽  
Developmental Delay ◽  
Microarray Analysis ◽  
Lower Incidence ◽  
Clinical Phenotype ◽  
Microarray Technology ◽  
Dysmorphic Features ◽  
Low Copy Repeats ◽  
Nonallelic Homologous Recombination ◽  
Chromosome Regions

Concurrent cryptic microdeletion and microduplication syndromes have recently started to reveal themselves with the advent of microarray technology. Analysis has shown that low-copy repeats (LCRs) have allowed chromosome regions throughout the genome to become hotspots for nonallelic homologous recombination to take place. Here, we report a case of a 7.5-year-old girl who manifests microcephaly, developmental delay, and mild dysmorphic features. Microarray analysis identified a microduplication in chromosome 17q21.31, which encompasses theCRHR1, MAPT,andKANSL1genes, as well as a microdeletion in chromosome 7q31.33 that is localised within theGRM8gene. To our knowledge this is one of only a few cases of 17q21.31 microduplication. The clinical phenotype of patients with this microduplication is milder than of those carrying the reciprocal microdeletions, and suggests that the lower incidence of the former compared to the latter may be due to underascertainment.

Impact of low copy repeats on the generation of balanced and unbalanced chromosomal aberrations in mental retardation

2006 ◽  
Vol 115 (3-4) ◽  
pp. 247-253 ◽  
Author(s):  
F. Erdogan ◽  
W. Chen ◽  
M. Kirchhoff ◽  
V.M. Kalscheuer ◽  
C. Hultschig ◽  
...  
Keyword(s):  
Mental Retardation ◽  
Chromosomal Aberrations ◽  
Low Copy Repeats

Conservation of hotspots for recombination in low-copy repeats associated with the NF1 microdeletion

2006 ◽  
Vol 38 (12) ◽  
pp. 1419-1423 ◽  
Author(s):  
Thomas De Raedt ◽  
Matthew Stephens ◽  
Ine Heyns ◽  
Hilde Brems ◽  
Daisy Thijs ◽  
...  
Keyword(s):  
Low Copy Repeats
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