Search results for "Supernumerary marker chromosome"
showing 5 items of 5 documents
The chromosomes of 16 molluscan species
1982
Abstract Chromosome numbers were determined for two species of Placophora, eleven species of Gastropoda, one species of Pelecypoda and two species of Cephalopoda. No heterotypic or supernumerary chromosome resulted from the analysis of meiotic and, when possible, of mitotic chromosomes. For this reason no positive evidence emerges for the presence of differentiated sex chromosome pairs. Data available seem to indicate that evolution within the Mollusca phylum has been accompanied by a decrease in both chromosome number and DNA content (according to Hinegardner, 1974), if we consider subclasses, orders and families (apart from the subclass Prosobranchia). On the contrary the primitive class …
Congenital hypopituitarism and multiple midline defects in a newborn with non-familial Cat Eye syndrome
2022
Abstract Background Cat eye syndrome (CES) is a rare chromosomal disease, with estimated incidence of about 1 in 100,000 live newborns. The classic triad of iris coloboma, anorectal malformations, and auricular abnormalities is present in 40% of patients, and other congenital defects may also be observed. The typical associated cytogenetic anomaly relies on an extra chromosome, derived from an inverted duplication of short arm and proximal long arm of chromosome 22, resulting in partial trisomy or tetrasomy of such regions (inv dup 22pter-22q11.2). Case presentation We report on a full-term newborn, referred to us soon after birth. Physical examination showed facial dysmorphisms, including …
FISH of supernumerary marker chromosomes (SMCs) identifies six diagnostically relevant intervals on chromosome 22q and a novel type of bisatellited S…
2005
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 …
Pigmentary mosaicism in hypomelanosis of Ito
1998
We report on a female with mental and motor retardation, facial dysmorphism, abnormal pigmentation reminiscent to hypomelanosis of Ito (HI), and karyotypic mosaicism involving a small supernumerary marker chromosome. The marker chromosome was defined by fluorescence in situ hybridisation (FISH) as a ring X chromosome with breakpoints in the juxtacentromeric region. FISH analysis showed that the ring does not include the XIST locus at the X-inactivation centre and, therefore, may not be subject to X inactivation. X-inactivation studies with the HUMARA (human androgen receptor) and FMR1 assay showed a skewed X-inactivation pattern (85:15) with preferential inactivation of the paternal X chrom…
Localization of amplified CAD genes on rearranged chromosomes of Chinese hamster cells
2012
Chinese hamster cell lines carrying an amplified CAD region were selected from V79,B7 cells by their resistance to N-phosphonacetyl-L-aspartate (PALA). In one of the selected cell lines, SP PALA (inf1) (supR) L, an acrocentric chromosome with abnormally elongated q arms was identified as a marker for the PALA-resistant phenotype. The marker chromosome carried a homogeneously staining region close to a telomeric nucleolar organizer region. In the same region, localization of amplified CAD sequences was demonstrated by in situ hybridization. The marker chromosome was found to undergo extensive rearrangements. In particular, dicentric chromosomes, occurring with an unusually high incidence, we…