Project description:Objective: Chromosomal 1q21.1 deletions and duplications are genomic disorders which are usually diagnosed postnatally. However, the genotype-phenotype correlations of 1q21.1 copy number variants (CNVs) during prenatal period are still not clear. This study aimed to provide a systematical summary of prenatal phenotypes for such genomic disorders. Methods: Twenty-six prenatal amniotic fluid samples diagnosed with 1q21.1 microdeletions/microduplications were obtained from pregnant women who opted for invasive prenatal testing. Karyotypic analysis and chromosomal microarray analysis (CMA) were performed for all cases simultaneously. The pregnancy outcomes and health conditions after birth for all cases were followed up. Meanwhile, prenatal cases with 1q21.1 microdeletions or microduplications in the literature were retrospectively collected. Results: Eleven pregnancies (11/8252, 0.13%) with 1q21.1 microdeletions and fifteen (15/8252, 0.18%) with 1q21.1 microduplications were identified. Among these 1q21.1 CNVs, four cases covered thrombocytopenia-absent radius (TAR) region, sixteen cases covered 1q21.1 recurrent microdeletion/microduplication region, and six cases covered all regions mentioned above. The prenatal abnormal ultrasound findings were recorded in four participants with 1q21.1 deletions and seven participants with 1q21.1 duplications. Finally, three cases with 1q21.1 deletions and five with 1q21.1 duplications terminated their pregnancies. Conclusion: 1q21.1 microdeletions were associated with increased nuchal translucency (NT), anomalies of urinary system and cardiovascular abnormalities, and 1q21.1 microduplications were correlated with cardiovascular malformations, nasal bone dysplasia and increased NT in prenatal setting. In addition, cerebral ventriculomegaly might be correlated with 1q21.1 microduplications. Considering the variable expressivity and incomplete penetrance of 1q21.1 CNVs, long term follow up after birth should be carried out for these cases. We identified 26 fetuses carrying the 1q21.1 microdeletions and microduplications using chromosomal microarray analysis. And diverse prenatal phenotypes and the critical genes involved in the deleted/duplicated regions were described in this study.

Project description:Background: Chromosomal 16p11.2 deletions and duplications are genomic disorders which are characterized by neurobehavioral abnormalities, obesity, congenital abnormalities and so on. However, the prenatal phenotypes of 16p11.2 copy number variations (CNVs) are still not well described till now. This study aimed to provide an elaborate summary of intrauterine phenotypic features for such genomic disorders. Methods: Twenty prenatal amniotic fluid samples diagnosed with 16p11.2 microdeletions/microduplications were obtained from pregnant women who opted for invasive prenatal testing. Karyotypic analysis and chromosomal microarray analysis (CMA) were performed in parallel. The pregnancy outcomes and health conditions after birth for all cases were followed up. Meanwhile, we made a pooled analysis on the prenatal phenotypes for the published cases carrying 16p11.2 CNVs. Results: 20 fetuses (20/20884, 0.10%) with 16p11.2 CNVs were identified: five 16p11.2 BP2-BP3 deletion, ten 16p11.2 BP4-BP5 deletion and five 16p11.2 BP4-BP5 duplication. Abnormal ultrasound findings were recorded in ten participants with 16p11.2 deletions.Various degrees of intrauterine phenotypic features, ranging from normal to abnormal, were observed. No ultrasound abnormalities were observed for all 16p11.2 duplication cases during the pregnancy period. For 16p11.2 deletions, eleven cases terminated their pregnancies. For 16p11.2 duplications, four cases gave birth to healthy neonates except one was lost to follow up. Conclusions: Diverse prenatal phenotypes were presented in 16p11.2 CNVs, ranging from normal to abnormal. For 16p11.2 BP4-BP5 deletion, the most common structural and non-structural abnormalities were the abnormality of the vertebral column or rib and thickened nuchal translucency, respectively. 16p11.2 BP2-BP3 deletion might be closely associated with fetal growth restriction and single umbilical artery. No representative ultrasound findings for 16p11.2 duplication were observed till now. Considering the variable expressivity and incomplete penetrance of 16p11.2 CNVs, long term follow up after birth should be carried out for these cases. We identified 20 fetuses carrying the 16p11.2 microdeletions and microduplications using chromosomal microarray analysis. And diverse prenatal phenotypes and the critical genes involved in the deleted/duplicated regions were described in this study.

Dataset Information

The NICHD Prenatal Microarray Study

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