scispace - formally typeset
Search or ask a question
Topic

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.


Papers
More filters
Journal ArticleDOI
TL;DR: Cytogenetic analysis was carried out in 100 tissue specimens from 88 patients with bladder cancer, finding various chromosomal abnormalities, numerical as well as structural, found.

8 citations

Journal ArticleDOI
TL;DR: In this paper, a 46,XX, 18 r chromosome set was found in a 12-year-old with mental deficiency and slight malformations, and the tritiated thymidine incorporation pattern in the ring chromosome was similar to that of the normal 18 r.
Abstract: In a girl affected by mental deficiency and slight malformations, a 46,XX, 18r chromosome set was found. Metaphases with irregularly sized or absent rings amounted to 14% in peripheral blood cultures. Tritiated thymidine incorporation pattern in the ring chromosome was similar to that of the normal 18 chromosome.

8 citations

Journal ArticleDOI
TL;DR: A further case of ring chromosome 15 in a 12-year-old boy with growth failure is described and he had minor congenital anomalies, but almost normal intelligence.
Abstract: A further case of ring chromosome 15 in a 12-year-old boy with growth failure is described. He had minor congenital anomalies, but almost normal intelligence.

8 citations

Journal ArticleDOI
TL;DR: A 10-year-old female who was referred for a cytogenetic analysis because she developed an alopecia universalis is reported, found to have a mosaic 45,X/46,X,+r and an unexpectedly mild phenotype in her patient.
Abstract: Rearranged X chromosome in Turner syndrome (TS) are generally well tolerated but in cases of ring X chromosomes and of X/autosome translocations the incidence of mental retardation and other congenital abnormalities can be significantly higher. These abnormal phenotypes can be ascribed to failed or partial X inactivation. Here, we report a 10-year-old female who was referred for a cytogenetic analysis because she developed an alopecia universalis. The patient, of normal intelligence, had been found to have traits of TS, especially short stature. A first cytogenetic analysis showed a no mosaic 45,X karyotype. Since, the risk of developing gonadoblastoma in TS patients with mosaicism for a Y derivative chromosome and because association of alopecia universalis and TS is uncommon, fluorescence in situ hybridization (FISH) was performed to search for a second cell population. Our patient was found to have a mosaic 45,X/46,X,+r. FISH analysis using sex chromosome probes permitted us to identify the very small marker as a ring X chromosome, detected in 90% of cells. The ring appeared to be formed almost totally of alphoid sequences with breakpoints in the juxtacentromeric region. The r(X) does not include the XIST locus and may, therefore, not be subject to X-inactivation. Unexpectedly mild phenotype in our patient and its association with alopecia universalis will be discussed.

8 citations

Journal ArticleDOI
TL;DR: In this article, an infant was reported who presented with a de novo 21;21 translocation trisomy 21 and an atypical phenotype for Down syndrome (DS), which included microcephaly, small stature, downslanting palpebral fissures, absent Brushfield spots, moderate micrognathia, left ptosis, left torticollis, severe developmental delay, seizures, and hypertonia.
Abstract: An infant is reported who presented with a de novo 21;21 translocation trisomy 21 and an atypical phenotype for Down syndrome (DS). Findings included microcephaly, small stature, downslanting palpebral fissures, absent Brushfield spots, moderate micrognathia, left ptosis, left torticollis, severe developmental delay, seizures, and hypertonia. Further clinical evaluation using both the diagnostic criteria for DS and the Jackson checklist of 25 signs was inconsistent with the diagnosis for DS. Blood karyotype revealed: 46,XX,+21,dic(21;21) (p11.2;p11.2). Fluorescence in situ hybridization (FISH) analysis confirmed the trisomy 21 translocation. Both parents had normal karyotypes. Chromosome and FISH analyses were performed on skin fibroblasts. These studies revealed mosaicism for a translocation trisomy 21 cell line as wel as a second cell line consisting of one normal chromosome 21 and a ring chromosome 21 derived from translocation 21q21q which appeared to have a deletion of the critical region for DS involving the distal portion of the thelong arm of chromosome 21. The chromosome findings illustrate an atypical phenotype in the spectrum of mosaic DS and suggest possible mechanisms for the variability of the phenotype. It also emphasizes the importance of evaluating other tissues for mosaicism when presented with atypical clinical findings.

8 citations


Network Information
Related Topics (5)
Missense mutation
18.5K papers, 806.1K citations
83% related
Chromosome
17.5K papers, 660K citations
82% related
Gene mutation
41.4K papers, 1.3M citations
80% related
Germline mutation
14.4K papers, 799.6K citations
80% related
Mutation
45.2K papers, 2.6M citations
79% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202310
202221
202123
202019
201919
201836