A case of an infertile male with a small supernumerary marker chromosome negative for M-FISH and containing only heterochromatin

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.

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Presumed mutation in a microsatellite marker mimicking segmental uniparental disomy in a case of a small supernumerary marker chromosome detected at prenatal diagnosis

Clinical Genetics ◽

10.1034/j.1399-0004.2003.00102.x ◽

2003 ◽

Vol 64 (2) ◽

pp. 168-171 ◽

Cited By ~ 4

Keyword(s):

Prenatal Diagnosis ◽

Microsatellite Marker ◽

Marker Chromosome ◽

Uniparental Disomy ◽

Small Supernumerary Marker Chromosome

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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

Cytogenetic and Genome Research ◽

10.1159/000494822 ◽

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.

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Prenatal diagnosis and molecular cytogenetic characterization of a small supernumerary marker chromosome derived from inv dup(15)

Taiwanese Journal of Obstetrics and Gynecology ◽

10.1016/j.tjog.2020.05.019 ◽

2020 ◽

Vol 59 (4) ◽

pp. 580-585

Author(s):

Chih-Ping Chen ◽

Hsiang-Yu Lin ◽

Liang-Kai Wang ◽

Schu-Rern Chern ◽

Peih-Shan Wu ◽

...

Keyword(s):

Prenatal Diagnosis ◽

Marker Chromosome ◽

Molecular Cytogenetic ◽

Small Supernumerary Marker Chromosome ◽

Cytogenetic Characterization

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

Cytogenetic and Genome Research ◽

10.1159/000494682 ◽

2018 ◽

Vol 156 (4) ◽

pp. 173-178 ◽

Cited By ~ 1

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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