Project description:Chromosomal microarray analysis (CMA) in prenatal diagnosis detects copy number variations (CNVs) in many fetuses; however, the low penetrance and phenotypic diversity of CNVs complicate genetic counseling, resulting in limited understanding of intrauterine ultrasound phenotypes linked to CNVs. In a retrospective analysis of 25,000 cases at Fujian Maternal and Child Health Hospital, 18,000 pregnant women underwent SNP array testing (December 2015 to June 2023).
Project description:This study aimed to evaluate the clinical value of copy number variations (CNVs) in fetuses with ultrasonic soft markers. Among 1131 fetuses, 729 had single ultrasonic soft marker, 322 had two ultrasonic soft markers, and 80 had three or more ultrasonic soft markers. All fetuses underwent single nucleotide polymorphism (SNP) array analysis. Among 1131 fetuses with ultrasonic soft markers, 46 had chromosomal abnormalities. In addition to the 46 fetuses with chromosomal abnormalities consistent with the results of the karyotyping analysis, the SNP array identified additional 6.1% (69/1131) abnormal CNVs. No significant difference was found in the rate of abnormal CNVs among the groups. The SNP array can fully complement conventional karyotyping in fetuses with ultrasonic soft markers, improve detection rate of chromosomal abnormalities, and affect pregnancy outcomes.
Project description:Although pulmonary stenosis (PS) is relatively common, the genetic etiology of congenital PS in fetuses is poorly studied. We used karyotype analysis and chromosomal microarray analysis (CMA) to investigate the genetic aberrations associated with PS in fetuses.
Project description:The Affymetrix CytoScan 750K Array chip contains 200000 SNP markers and 550000 CNV markers, distributed across the entire human genome at an average density of approximately 1 marker/4kb (not covering all loci of the entire chromosome genome). It is used to detect clinically significant chromosomal microdeletions/microduplications, chromosomal subtelomer deletion syndrome, and other abnormal chromosomal copy number variations (CNVs) as well as loss of heterozygosity (LOH). In a case study of Zhangzhou Municipal Hospital of Fujian Province, copy number variation detection was performed on a fetus with Silver-Russell syndrome using CytoScan 750K Array chip, and variations in the corresponding region were identified.
Project description:Copy-number variants (CNVs) are large-scale amplifications or deletions of DNA that can drive rapid adaptive evolution and result in large-scale changes in gene expression. Whereas alterations in the copy number of one or more genes within a CNV can confer a selective advantage, other genes within a CNV can decrease fitness when their dosage is changed. Dosage compensation - in which the gene expression output from multiple gene copies is less than expected - is one means by which an organism can mitigate the fitness costs of deleterious gene amplification. Previous research has shown evidence for dosage compensation at both the transcriptional level and at the level of protein expression; however, the extent of compensation differs substantially between genes, strains, and studies. Here, we investigated sources of dosage compensation at multiple levels of gene expression regulation by defining the transcriptome, translatome and proteome of experimentally evolved yeast (Saccharomyces cerevisiae) strains containing adaptive CNVs.