Centromere Fissions, Complementary Isochromosomes, Telomeric Fusions, Balancing Supernumerary Chromosomes, Neocentromeres, Jumping Translocations, and Chromothripsis

2018 ◽  
Author(s):  
R. J McKinlay Gardner ◽  
David J Amor
Keyword(s):  
Chromosomal Rearrangements ◽  
Marker Chromosome ◽  
Chromosome Count ◽  
Supernumerary Chromosome ◽  
Submetacentric Chromosome ◽  
Supernumerary Chromosomes ◽  
Complex Rearrangement ◽  
Small Supernumerary Marker Chromosome

This chapter reviews a number of very rare chromosomal rearrangements: centromere fissions, complementary isochromosomes, telomeric fusions, balancing supernumerary chromosomes, neocentromeres, jumping translocations, and chromothripsis. Centromere fission results when a metacentric or submetacentric chromosome splits at the centromere, giving rise to two stable telocentric products. The Robertsonian fission reverses the fusion that had originally generated it. Telomeric fusion leads to a 45-chromosome count. With the balanced complementary isochromosome carrier, two stable exactly metacentric products are generated. A balancing small supernumerary marker chromosome contains material deleted from the normal homolog. A supernumerary chromosome lacking a normal centromere can become stable and functional due to the generation of a neocentromere. In jumping translocations, a segment can move from one chromosome to two or more recipient chromosomes. Chromothripsis takes complex rearrangement to a yet more complex level. The reproductive risks associated with each are noted.

scholarly journals Clinical Impact of Proximal Autosomal Imbalances

2012 ◽  
Vol 15 (2) ◽  
pp. 15-21 ◽  
Author(s):  
A.B. Hamid ◽  
A. Weise ◽  
M. Voigt ◽  
M. Bucksch ◽  
N. Kosyakova ◽  
...  
Keyword(s):  
Copy Number ◽  
Single Cell Analysis ◽  
Chromosomal Rearrangements ◽  
Marker Chromosome ◽  
Partial Trisomy ◽  
Clinical Impact ◽  
Cell Analysis ◽  
Small Supernumerary Marker Chromosome ◽  
Copy Numbers ◽  
Based Medicine

ABSTRACT Centromere-near gain of copy number can be induced by intra- or inter-chromosomal rearrangements or by the presence of a small supernumerary marker chromosome (sSMC). Interestingly, partial trisomy to hexasomy of euchromatic material may be present in clinically healthy or affected individuals, depending on origin and size of chromosomal material involved. Here we report the known minimal sizes of all centromere-near, i.e., proximal auto-somal regions in humans, which are tolerated; over 100 Mb of coding DNA are comprised in these regions. Additionally, we have summarized the typical symptoms for nine proximal autosomal regions including genes obviously sensitive to copy numbers. Overall, studying the carriers of specific chromosomal imbalances using genomics-based medicine, combined with single cell analysis can provide the genotype-phenotype correlations and can also give hints where copy-numbersensitive genes are located in the human genome.

scholarly journals Two Separate Cases: Complex Chromosomal Abnormality Involving Three Chromosomes and Small Supernumerary Marker Chromosome in Patients with Impaired Reproductive Function

Genes ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1511
Author(s):  
Tatyana V. Karamysheva ◽  
Tatyana A. Gayner ◽  
Vladimir V. Muzyka ◽  
Konstantin E. Orishchenko ◽  
Nikolay B. Rubtsov
Keyword(s):  
Genetic Counseling ◽  
Chromosome Rearrangement ◽  
Marker Chromosome ◽  
Reproductive Function ◽  
Small Supernumerary Marker Chromosome ◽  
Comprehensive Chromosome Screening ◽  
The Family ◽  
Multicolor Banding ◽  
The One

For medical genetic counseling, estimating the chance of a child being born with chromosome abnormality is crucially important. Cytogenetic diagnostics of parents with a balanced karyotype are a special case. Such chromosome rearrangements cannot be detected with comprehensive chromosome screening. In the current paper, we consider chromosome diagnostics in two cases of chromosome rearrangement in patients with balanced karyotype and provide the results of a detailed analysis of complex chromosomal rearrangement (CCR) involving three chromosomes and a small supernumerary marker chromosome (sSMC) in a patient with impaired reproductive function. The application of fluorescent in situ hybridization, microdissection, and multicolor banding allows for describing analyzed karyotypes in detail. In the case of a CCR, such as the one described here, the probability of gamete formation with a karyotype, showing a balance of chromosome regions, is extremely low. Recommendation for the family in genetic counseling should take into account the obtained result. In the case of an sSMC, it is critically important to identify the original chromosome from which the sSMC has been derived, even if the euchromatin material is absent. Finally, we present our view on the optimal strategy of identifying and describing sSMCs, namely the production of a microdissectional DNA probe from the sSMC combined with a consequent reverse painting.

SEX AND SUPERNUMERARY CHROMOSOMES IN THE DIOECIOUS GRASS SOHNSIA FILIFOLIA

1972 ◽  
Vol 14 (1) ◽  
pp. 175-180 ◽  
Author(s):  
D. N. Singh
Keyword(s):  
Sex Determination ◽  
Y Chromosome ◽  
Supernumerary Chromosome ◽  
The Other ◽  
Male Plant ◽  
Diploid Male ◽  
Male And Female ◽  
Supernumerary Chromosomes ◽  
Determination System ◽  
Sex Determination System

A dioecious grass Sohnsia filifolia (Fourn.) Airy Shaw (Syn. Calamochloa filifolia Fourn.) from Mexico has been found to have 2n = 20 chromosomes in both male and female plants. The staminate plants have one chromosome much longer than the other chromosomes of the complement. One pistillate plant was found to have 30 chromosomes, among which the largest chromosome is quite similar to the largest component of the diploid male plant. The longest chromosome has been designated as the Y chromosome. An XY-mechanism of the Drosophilia type has been suggested for the sex determination system in this species. One small supernumerary chromosome was observed in the microsporocytes of some male plants, but was absent in roots.

A Familial Small Supernumerary Marker Chromosome 15 Associated with Cryptic Mosaicism with Two Different Additional Marker Chromosomes Derived de novo from Chromosome 9: Detailed Case Study and Implications for Recurrent Pregnancy Loss

2018 ◽  
Vol 156 (4) ◽  
pp. 179-184
Author(s):  
Vida Čulić ◽  
Ruzica Lasan-Trcić ◽  
Thomas Liehr ◽  
Igor N. Lebedev ◽  
Maja Pivić ◽  
...  
Keyword(s):  
Pregnancy Loss ◽  
De Novo ◽  
Marker Chromosome ◽  
Chromosome 9 ◽  
Chromosome 15 ◽  
Normal Female ◽  
Fish Analysis ◽  
Spontaneous Abortions ◽  
Small Supernumerary Marker Chromosome ◽  
Trisomy 9

We report a case of familial small supernumerary marker chromosome 15 in a phenotypically normal female with 4 recurrent spontaneous abortions and a healthy child. The initial karyotype showed a small, bisatellited, apparently metacentric marker chromosome, 47,XX,+idic(15)(q11.1), maternally inherited. The proband's mother was mosaic for the idic(15)(q11.1) without pregnancy loss. Reexamination of the proband's karyotype revealed cryptic mosaicism for 1 ring and 1 minute chromosome derived de novo from chromosome 9 in 2% of the metaphases. In FISH analysis, the patient's karyotype was mos 47,XX,+idic(15)(q11.1)mat[100]/49,XX,+idic(15)(q11.1)mat,+r(9;9;9;9),+der(9)dn[2]. The second spontaneous abortion had trisomy 9 (47,XX,+9); the third had mosaic trisomy 9 in 21% of the nuclei and isodicentric chromosome 15 in 36% of the nuclei (mos 48,XN,+9,+idic(15)(q11.1)/47,XN,+9/47,XN,+idic(15)(q11.1)/46,XN). The first and fourth abortions were not cytogenetically studied. The cause of the spontaneous abortions in this patient is likely the cryptic mosaicism for ring and minute chromosomes 9, and gonadal mosaicism is most probable, due to the 2 abortions.

Chromosomal rearrangements in rock wallabies, Petrogale (Marsupialia: Macropodidae). III. G-banding analysis of Petrogale inornata and P. penicillata

Genome ◽  
1990 ◽  
Vol 33 (6) ◽  
pp. 798-802 ◽  
Author(s):  
M. D. B. Eldridge ◽  
R. L. Close ◽  
P. G. Johnston
Keyword(s):  
Acrocentric Chromosome ◽  
Chromosomal Rearrangements ◽  
Paracentric Inversion ◽  
Chromosome 3 ◽  
Chromosome 4 ◽  
Chromosome 5 ◽  
Cultured Fibroblasts ◽  
Submetacentric Chromosome ◽  
Ancestral Chromosome ◽  
Banding Analysis

The karyotypes of Petrogale inornata and the two currently recognised races of Petrogale penicillata were examined using G-banding from cultured fibroblasts. Petrogale inornata (2n = 22) was found to retain plesiomorphic chromosomes 3 and 4 but possessed an apomorphic inverted chromosome 5 (5i). This 5i appears identical with the 5i found in two other Queensland taxa, Petrogale assimilis and Petrogale godmani, and can be derived from the ancestral chromosome 5 by an extensive paracentric inversion or a centromeric transposition. Petrogale penicillata penicillata (2n = 22) and Petrogale penicillata herberti (2n = 22) both possess the synapomorphic acrocentric chromosome 3, which appears to differ from the plesiomorphic 3 by a small centromeric transposition. Petrogale p. penicillata was also found to be characterised by an apomorphic acrocentric chromosome 4, while P. p. herberti was characterised by an autapomorphic submetacentric chromosome 4. Both apomorphic chromosomes 4 can be related to the plesiomorphic chromosome 4 by centromeric transpositions. Thus although P. inornata is chromosomally distinct it is more closely related to other north Queensland taxa than it is to either P. p. penicillata or P. p. herberti.Key words: chromosomal rearrangements, G-banding, Marsupialia, Petrogale, Macropodidae.

Complex Small Supernumerary Marker Chromosome Leading to Partial 4q/21q Duplications: Clinical Implication and Review of the Literature

2018 ◽  
Vol 156 (4) ◽  
pp. 173-178 ◽  
Author(s):  
Fernanda T. Bellucco ◽  
Rodrigo A. Fock ◽  
Hélio R. de Oliveira-Júnior ◽  
Ana B. Perez ◽  
Maria I. Melaragno
Keyword(s):  
Genetic Counseling ◽  
Developmental Delay ◽  
Clinical Implication ◽  
Marker Chromosome ◽  
Accurate Diagnosis ◽  
Facial Dysmorphism ◽  
Review Of The Literature ◽  
Small Supernumerary Marker Chromosome ◽  
Wide Range ◽  
Similar Phenotype

Complex small marker chromosomes (sSMCs) consist of chromosomal material derived from more than 1 chromosome. Complex sSMCs derived from chromosomes 4 and 21 are rare, with only 7 cases reported. Here, we describe a patient who presented with a complex sSMC derived from a maternal translocation between chromosomes 4 and 21, which was revealed by G-banding, MLPA, and array techniques. The marker chromosome der(21)t(4;21)(q32.1; q21.2)mat is composed of a 25.6-Mb 21pterq21.2 duplication and a 32.1-Mb 4q32.1q35.2 duplication. In comparison to patients with sSMCs derived from chromosomes 4 and 21, our patient showed a similar phenotype with neuropsychomotor developmental delay and facial dysmorphism as the most important finding, being a composition of the findings found in pure 4q and 21q duplications. The wide range of phenotypes associated with sSMCs emphasizes the importance of detailed cytogenomic analyses for an accurate diagnosis, prognosis, and genetic counseling.

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