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Ring chromosome

About: Ring chromosome is a research topic. Over the lifetime, 1546 publications have been published within this topic receiving 31061 citations. The topic is also known as: supernumerary circular chromosome.


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Journal ArticleDOI
TL;DR: An individual with autism and a coloboma of the eye carrying a mosaicism for a ring chromosome consisting of an inverted duplication of proximal chromosome 14 is described, suggesting that position effects need to be taken into account, when analyzing genotype–phenotype correlations based on chromosomal imbalances.
Abstract: We describe an individual with autism and a coloboma of the eye carrying a mosaicism for a ring chromosome consisting of an inverted duplication of proximal chromosome 14. Of interest, the ring formation was associated with silencing of the amisyn gene present in two copies on the ring chromosome and located at 300 kb from the breakpoint. This observation lends further support for a locus for autism on proximal chromosome 14. Moreover, this case suggests that position effects need to be taken into account, when analyzing genotype-phenotype correlations based on chromosomal imbalances.

23 citations

Journal ArticleDOI
TL;DR: A female infant manifesting multiple congenital anomalies including cyclopian deformity is described, which revealed a ring chromosome in place of one of the normal No. 18 homologs.
Abstract: A female infant manifesting multiple congenital anomalies including cyclopian deformity is described. Chromosomal analysis revealed a ring chromosome in place of one of the normal No. 18 homologs. Identification of this structurally abnormal chromosome was confirmed by fluorescence and “giemsa banding” techniques.

23 citations

Journal ArticleDOI
TL;DR: The ring chromosome lacked the short arms of the two translocated chromosomes 15 and was duplicated for a portion of the long arms near the centromere, probably cen leads to q13.
Abstract: We describe a boy with a ring chromosome 15, showing the manifestations characteristic of this condition, ie, growth deficiency and unusual facial appearance with minor anomalies. The ring was derived from a t(15q;15q) chromosome of the mother, who had also had four spontaneous abortions. The respective karyotypes were 45,XX, -15,-15,+t(15q;15q) (mother) and 46,XY,-15,+r(15q;15q)mat (15q13 leads to cen leads to 15q26)(son). The ring chromosome lacked the short arms of the two translocated chromosomes 15 and was duplicated for a portion of the long arms near the centromere, probably cen leads to q13. Data from enzyme assays suggest that this duplicated region carries the alpha-mannosidase gene.

23 citations

Journal ArticleDOI
TL;DR: A ring chromosome No. 9 identified by quinacrine staining was found in a 22‐year‐old mentally retarded girl with low stature, fissure of the palate, protruding lower lip and valgus deformity of the knees.
Abstract: A ring chromosome No. 9 identified by quinacrine staining was found in a 22-year-old mentally retarded girl with low stature, fissure of the palate, protruding lower lip and valgus deformity of the knees. The patient showed heterozygosity (type II) for cystinuria. The ring was unstable and showed different configurations.

23 citations

Journal ArticleDOI
TL;DR: Six distinct intervals on 22q to be relevant for FISH diagnostics are found and it is proposed to characterize SMCs(22) using DNA probes corresponding to these intervals.
Abstract: Supernumerary marker chromosomes (SMCs) are frequently found at pre- and postnatal cytogenetic diagnosis and require identification. A disproportionally large subset of SMCs is derived from the human chromosome 22 and confers tri- or tetrasomy for the cat eye chromosomal region (CECR, the proximal 2 Mb of chromosome 22q) and/or other segments of 22q. Using fluorescence in situ hybridization (FISH) and 15 different DNA probes, we studied nine unrelated patients with an SMC(22) that contained the CECR. Five patients showed the small (type I) cat eye syndrome (CES) chromosome and each one had the larger (type II) CES chromosome, small ring chromosome 22, der(22)t(11;22) extrachromosome, and a novel type of bisatellited SMC(22) with breakpoints outside the low-copy repeats (LCRs22). By size and morphology, the novel bisatellited SMC(22) resembled the typical (types I and II) CES chromosomes, but it might have been associated with the chromosome 22q duplication syndrome, not CES. This SMC included a marker from band 22q12.3 and conferred only one extra copy each of the 22 centromere, CECR, and common 22q11 deletion area. There has been no previous report of a bisatellited SMC(22) predicting the chromosome 22q duplication syndrome. Accounting for the cytogenetic resemblance to CES chromosomes but different makeup and prognosis, we propose naming this an atypical (type III) CES chromosome. In this study, we found six distinct intervals on 22q to be relevant for FISH diagnostics. We propose to characterize SMCs(22) using DNA probes corresponding to these intervals.

23 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202310
202221
202123
202019
201919
201836