scholarly journals Prenatal diagnosis and genetic counseling in a fetus associated with risk of Angelman syndrome with a small supernumerary marker chromosome derived from chromosome 22

2016 ◽  
Vol 9 (1) ◽  
Author(s):  
Yu-an Hu ◽  
Yingxia Cui ◽  
Xiaobo Fan ◽  
Qiuyue WU ◽  
Weiwei Li ◽  
...  
Keyword(s):  
Genetic Counseling ◽  
Prenatal Diagnosis ◽  
Angelman Syndrome ◽  
Marker Chromosome ◽  
Chromosome 22 ◽  
Small Supernumerary Marker Chromosome

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.

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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