Prenatal diagnosis and genetic analysis of small supernumerary marker chromosomes in the eastern chinese han population: A retrospective study of 36 cases.
Xiali Jiang, Bin Liang, Bilian Chen, Xiaoqing Wu, Yan Wang, Na Lin, Hailong Huang, Liangpu Xu
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引用次数: 0
Abstract
Background: Small supernumerary marker chromosomes (sSMCs) are additional chromosomes with unclear structures and origins, and their correlations with clinical fetal phenotypes remain incompletely understood, which reduces the accuracy of genetic counseling.
Methods: We conducted a retrospective analysis of a cohort of 36 cases of sSMCs diagnosed in our center. We performed G-banding and chromosomal microarray analysis (CMA). The resulting karyotypes were compared with case reports in the literature and various databases including OMIM, DECIPHER, ClinVar, ClinGen, ISCA, DGV, and PubMed.
Results: Karyotype analysis data revealed that 19 out of 36 fetuses were mosaic. Copy number variants (CNVs) analysis results showed that 27 out of 36 fetuses harbored pathogenic/likely pathogenic variants. Among these 27 cases, 11 fetuses carried sex chromosome-related CNVs, including 4 female cases exhibiting Turner syndrome phenotypes and 7 cases showing Y chromosome deletions. In the remaining 16 fetuses with autosomal CNVs, 9 fetuses carried variants associated with Cat eye syndrome, Emanuel syndrome, Tetrasomy 18p, and 15q11-q13 duplication syndrome. Among these, 22 fetuses were terminated, and the remaining 5 fetuses were delivered and developed normally. Additionally, we identified a few variants with unclear pathogenicity.
Conclusion: Cytogenetic analysis is essential for identifying the pathogenicity of sSMCs and increasing the accuracy of genetic counseling.
期刊介绍:
Chromosome Research publishes manuscripts from work based on all organisms and encourages submissions in the following areas including, but not limited, to:
· Chromosomes and their linkage to diseases;
· Chromosome organization within the nucleus;
· Chromatin biology (transcription, non-coding RNA, etc);
· Chromosome structure, function and mechanics;
· Chromosome and DNA repair;
· Epigenetic chromosomal functions (centromeres, telomeres, replication, imprinting,
dosage compensation, sex determination, chromosome remodeling);
· Architectural/epigenomic organization of the genome;
· Functional annotation of the genome;
· Functional and comparative genomics in plants and animals;
· Karyology studies that help resolve difficult taxonomic problems or that provide
clues to fundamental mechanisms of genome and karyotype evolution in plants and animals;
· Mitosis and Meiosis;
· Cancer cytogenomics.