Molecular cytogenetic characterization of a de novo supernumerary ring chromosome 7 resulting in partial trisomy, tetrasomy, and hexasomy in a child with dysmorphic signs, congenital heart defect, and developmental delay

Beust, G. von; Sauter, Simone M.; Liehr, Thomas; Burfeind, Peter; Bartels, Iris; Starke, Heike; Eggeling, Ferdinand von; Zoll, Barbara

doi:10.1002/ajmg.a.30835

Cited by 10 publications

(5 citation statements)

References 12 publications

(20 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Monosomy 7, one complete ring, supernumerary large rings, and duplicated rings of chromosome 7, were detected. Most previous reported cases of supernumerary ring chromosome 7 showed a majority of cells with a normal karyotype, in addition to some cells with a partial trisomy containing small rings [20-26]. Here we present a newborn girl that survived with a mosaic karyotype with a complete supernumerary ring chromosome 7 and a few monosomy 7 cells, without any cell with normal karyotype detected in peripheral lymphocytes.…”

Section: Discussionmentioning

confidence: 73%

Molecular cytogenetic analysis and clinical manifestations of a case with de novo mosaic ring chromosome 7

Tsai

Lee²,

Fang

et al. 2011

Mol Cytogenet

View full text Add to dashboard Cite

AimClinical and molecular cytogenetic investigations of a newborn girl exhibiting facial dysmorphism with developmental delay.MethodsPhenotypic evaluation was first applied to examine the proband's developmental status. Computed tomography and colour transcranial Doppler were used then to investigate her brain structure and function. Subsequently, chromosomal abnormalities were examined by karyotyping and fluorescent in situ hybridization was performed to investigate size of fragments lost at the two distal ends of the ring chromosome 7. In addition, multicolour banding was applied to rule out structural rearrangement occurs in between the ring chromosome 7.ResultsThe proband was born with mosaic supernumerary ring chromosome 7, without a normal karyotype detected in the peripheral blood lymphocytes. The distal arm of chromosome 7p (at least 255 kb from the telomere) was part of an extra ring chromosome 7. In addition, the distal arm of 7q, at least 8 kb from the telomere, was missing. There was no other chromosomal rearrangement detected by multicolour banding.InterpretationThis is the 19th reported case of complete ring chromosome 7 mosaicism and the first survived case with mosaic supernumerary ring 7 without a normal karyotype detected in the peripheral lymphocytes.

show abstract

Section: Discussionmentioning

confidence: 73%

Molecular cytogenetic analysis and clinical manifestations of a case with de novo mosaic ring chromosome 7

Tsai

Lee²,

Fang

et al. 2011

Mol Cytogenet

View full text Add to dashboard Cite

show abstract

“…In addition, one fetus with chromosome 7 tetrasomy (48,XN,+7,+7) was found in this study. Study has shown that partial tetrasomy of chromosome 7 can cause dysmorphic signs, congenital heart defect, and developmental delay (von Beust et al, 2005).…”

Section: Discussionmentioning

confidence: 99%

Analysis of Genomic Copy Number Variation in Miscarriages During Early and Middle Pregnancy

Huang

Zhang

et al. 2021

Front. Genet.

View full text Add to dashboard Cite

The purpose of this study was to explore the copy number variations (CNVs) associated with miscarriage during early and middle pregnancy and provide useful genetic guidance for pregnancy and prenatal diagnosis. A total of 505 fetal specimens were collected and CNV sequencing (CNV-seq) analysis was performed to determine the types and clinical significance of CNVs, and relevant medical records were collected. The chromosomal abnormality rate was 54.3% (274/505), among which the numerical chromosomal abnormality rate was 40.0% (202/505) and structural chromosomal abnormality rate was 14.3% (72/505). Chromosomal monosomy mainly occurred on sex chromosomes, and chromosomal trisomy mainly occurred on chromosomes 16, 22, 21, 15, 13, and 9. The incidence of numerical chromosomal abnormalities in ≥35 year-old age pregnant women was significantly higher than <35 year-old age group. The highest incidence of pathogenic CNV (pCNV) was found in fetuses at ≤6 weeks of pregnancy (5.26%), and the incidence of variants of unknown significance (VOUS) CNVs decreased gradually with the increase of gestational age. The rate of chromosomal abnormalities of fetuses in early pregnancy (59.5%) was higher than that of fetuses in middle pregnancy (27.2%) (p < 0.001). There were 168 genes in VOUS + pCNV regions. 41 functions and 12 pathways (p < 0.05) were enriched of these genes by Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. Some meaningful genetic etiology information such as genes and pathways has been obtained, it may provide useful genetic guidance for pregnancy and prenatal diagnosis.

show abstract

“…4). The boy was able to correctly pronounce only a very small number of words, but scored at a much higher ability level on receptive vocabulary and on nonlanguage tasks.Individuals with larger chromosome 7 duplications that include 7q11.23 also present with speech and language impairment, along with mild developmental delay (Refs 72,86,87,88,89,90,91). A review of these reported patients also suggests the presence of a subtle but recognisable facial phenotype, consisting of a high broad nose, posteriorly rotated ears, high arched palate and short philtrum.…”

mentioning

confidence: 99%

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

Osborne

Mervis

2007

Expert Rev. Mol. Med.

128

View full text Add to dashboard Cite

The 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.Although childhood disorders of cognition, language and behaviour are extremely common (WHO: http://www.who.int/en/), causative genes have remained particularly refractory to traditional genetic approaches since the disorders themselves are often sporadic in nature and their causes complex and both genetically and environmentally heterogeneous. Genomic disorders, caused by the gain, loss or inversion of specific chromosome regions, are often characterised by neurodevelopmental phenotypes and present a unique opportunity to identify genes and pathways that are necessary for proper brain development and function (Ref. 1).One such region that is prone to genomic rearrangement is the Williams-Beuren syndrome (WBS) locus at chromosome 7q11.23. This 1.5 million base pair region has been shown to commonly undergo deletion, duplication or inversion through unequal meiotic recombination between highly similar flanking segments of DNA (Refs 2,3,4 CIHR Author Manuscript CIHR Author Manuscript CIHR Author Manuscriptthe region is not associated with any clinical features, but can predispose the chromosome to subsequent unequal recombination during the next round of meiosis. The inversion is estimated to be present at a frequency of 1 in 20, but there is a fivefold increase in carrier frequency in the parents of children with the WBS deletion (Refs 3,5). Deletion and duplication of 7q11.23 result in distinct patterns of cognitive impairment, both of which impact on language and speech abilities, albeit in very different ways (Refs 4, 6, 7). The WBS deletion has an estimated frequency of between 1 in 7500 and 1 in 20 000 (Refs 8, 9). As a result of the mechanism of genomic rearrangement, duplication should occur at a similar frequency; however, owing to its very recent discovery, the population fre...

show abstract

Molecular cytogenetic characterization of a de novo supernumerary ring chromosome 7 resulting in partial trisomy, tetrasomy, and hexasomy in a child with dysmorphic signs, congenital heart defect, and developmental delay

Cited by 10 publications

References 12 publications

Molecular cytogenetic analysis and clinical manifestations of a case with de novo mosaic ring chromosome 7

Molecular cytogenetic analysis and clinical manifestations of a case with de novo mosaic ring chromosome 7

Analysis of Genomic Copy Number Variation in Miscarriages During Early and Middle Pregnancy

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

Contact Info

Product

Resources

About