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.

Interstitial Duplication and Distal Deletion in a Ring Chromosome 13 with Pulmonary Atresia and Ventricular Septal Defect: A Case Report and Review of Literature

Abstract: We report on a newborn female infant with a unique ring chromosome 13. Prenatal findings include intrauterine growth restriction (IUGR); ventricular septal defect (VSD), overriding aorta, and pulmonary stenosis. Postnatal examination found mild dysmorphic features of flat fontanels and hypertelorism. Echocardiogram confirmed the diagnosis of Tetralogy of Fallot (TOF), pulmonary atresia (PA) and VSD. Cytogenetic analysis detected a mosaic pattern of a ring chromosome 13, monosomy 13 and dicentric ring chromosome in about 90%, 9% and 1% of blood lymphocytes, respectively. Oligonucleotide array comparative genomic hybridization (aCGH) analysis revealed a 28.476 Mb interstitial duplication of 13q14.11-q21.33 and a 10.217 Mb distal deletion of 13q33.2-q34. Review of the literature suggested three groups of ring chromosome 13 with variable phenotypes based on the size of 13q deletions and noted two cases of ring chromosome 13 with a distal deletion defined by genomic analysis. A heat map of ring chromosome 13 phenotypes was constructed. The present case represents a new group of ring chromosome 13 with compound segmental duplication and deletion. This study demonstrates the importance of genomic characterization of constitutional ring chromosome for better disease classification and phenotype correlation. [N A J Med Sci. 2013;6(4):208-212. DOI: 10.7156/najms.2013.0604208]

CGH and direct diagnosis of mosaic structural chromosomal abnormalities: description of a mosaic ring chromosome 17 and review of the literature

Abstract: We report the characterisation of a de novo supernumerary chromosome marker in a mosaic state (50%) by comparative genomic hybridisation (CGH) in an 8-year-old child with hypotonia, dysmorphia and mild-to-moderate mental retardation. We describe the combined use of CGH and fluorescence in situ hybridisation (FISH) to identify the origin of the additional chromosomal material. Visual analysis of 10 CGH-metaphase spreads revealed a gain of green fluorescent signal on pericentromeric region of chromosome 17. The CGH finding was confirmed by FISH analysis using a whole chromosome 17 paint, a chromosome 17 centromeric probe and the probe coding for the Smith-Magenis locus in 17p11.2. These results show that performing both CGH and FISH in combination with classical karyotyping will certainly allow the identification of imbalanced chromosome rearrangements and, by the way, allow the identification of genes involved in mental retardation and/or malformative pathology.

Trisomy/partial monosomy mosaicism of no. 13 pair [46, XX, −13, +rob(13q13q)/46, XX, r(13) (p11q34)]

Abstract: A mentally retarded and malformed girl is described. Her karyotype was 46, XX, −13, +rob(13q 13q)/46, XX, r(13) (p11q34),i.e., she was trisomic for a 13 in about 75% of the cells and partially monosomic for a distal part of 13q in about 25% of the cells. Clinical features were compared with those of cases with either trisomy or partial monosomy 13.

A case of D13 ring chromosome.

Abstract: A case of D ring chromosome identified with trypsin banding as a 13 with loss of the bands p12 and q34 is reported. The clinical features characteristically associated with the loss of these specific segments were present.