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.
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TL;DR: Phenytoin was added, and he continued to have one to two seizures per month for the next year, and the seizure frequency increased to a daily basis.
Abstract: quency increased to a daily basis. These seizures were associated with a clonic component. Phenytoin was added, and he continued to have one to two seizures per month for the next year. At age 3 years, the seizure frequency again increased, and staring spells were also noted. A genetic study was done with cells obtained from peripheral blood, cultured, and harvested. A total of 35 cells were ex-
13 citations
TL;DR: Fluorescent in situ hybridization using X and Y chromosome-specific alpha satellite DNA probes hybridizing to loci DXZ1 and DYZ3 was performed and demonstrated that the marker/ring chromosome in each of these 6 patients originated from the X.
Abstract: Fluorescent in situ hybridization (FISH) using X and Y chromosome-specific alpha satellite DNA probes hybridizing to loci DXZ1 and DYZ3 was performed to identify the origin of ring/marker chromosomes in 6 patients with Ullrich-Turner syndrome (UTS). All patients had a mosaic karyotype, 5 with 45,X/46,X,r(?) and one with 45,X/46,X,mar. We demonstrated that the marker/ring chromosome in each of these 6 patients originated from the X. A timely knowledge of the X or Y origin of ring and marker chromosomes can be crucial in genetic counseling and medical management since the presence of Y chromosome material in phenotypic females is known to increase the risk for developing gonadoblastoma.
13 citations
TL;DR: It is concluded that the cri-du-chat phenotype in this patient is due to a submicroscopical lesion in the distal segment of the short arm of the abnormal No. 5 chromosome; without noticeable loss of chromatin, a break involved in a pericentric inversion seems to have altered a chromosome section of crucial importance.
Abstract: A malformed girl presenting the typical clinical features of the cri-du-chat syndrome is described. Her karyotype contains three grossly abnormal chromosomes, a 5p–q+, a ring C and a 15q+. Formally, a minimum of six breaks is involved in the origin of this complex anomaly. Based on autoradiographic evidence, it is concluded that the cri-du-chat phenotype in this patient is due to a submicroscopical lesion in the distal segment of the short arm of the abnormal No. 5 chromosome; without noticeable loss of chromatin, a break involved in a pericentric inversion, 5p–q+ seems to have altered a chromosome section of crucial importance. Such an interpretation is supported by the reports of cri-du-chat cases with morphologically normal No. 5 chromosomes. The additional structural rearrangements in the child’s karyotype apparently did not affect his phenotype. Blood cultures from the child’s mother showed acentric fragments and ring chromosomes in 5.3% of 225 analyzed cells. Possible causes for this high aberration rate are discussed.
13 citations
Journal Article•
TL;DR: The continuing abnormal chromosomal silhouette of this tumor supports the stemline cell concept for malignancies, even when applied to such relatively benign neoplasms as this noninvasive carcinoma of the bladder.
Abstract: In a recurrent noninvasive papillary carcinoma of the bladder cytogenetic analysis by the direct technique was carried out on cystoscopic biopsies obtained at 53 month intervals. Persistent similar karyotypic abnormalities including aneuploidy, and ring and other marker chromosomes, the hallmarks of invasive cancer, were present in both specimens. In the 1973 specimen, DNA banding was identified in 35 per cent of the metaphases and in 56 per cent of the karyotypes. The continuing abnormal chromosomal silhouette of this tumor supports the stemline cell concept for malignancies, even when applied to such relatively benign neoplasms as this noninvasive carcinoma of the bladder.
13 citations
TL;DR: The association of chromosome 18 partial deletions and immunoglobulin abnormalities suggests the presence of an as yet unrecognised gene with a pivotal role for immunoglOBulin production on chromosome 18.
Abstract: A patient with a mosaic karyotype 45,XX,-18/46,XX,dic r(18)/46, XX, r(18) with multiple phenotypic abnormalities and immunodeficiency was presented at the age of 14 years. Immunological investigation revealed markedly decreased IgG, IgA and in two of three evaluations also IgM levels. Although selective IgA deficiency is frequent in patients with a ring chromosome 18, this is the third patient described with decreased levels of other immunoglobulin isotypes. The association of chromosome 18 partial deletions and immunoglobulin abnormalities suggests the presence of an as yet unrecognised gene with a pivotal role for immunoglobulin production on chromosome 18.
13 citations