Prenatal phenotypes and pregnancy outcomes of fetuses with recurrent 1q21.1 microdeletions and microduplications
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ABSTRACT: 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.
Project description:One in five people with Down syndrome (DS) are born with an atrioventricular septal defect (AVSD), an incidence 2,000 times higher than in the euploid population. The genetic loci that contribute to this risk are poorly understood. In this study, we tested two hypotheses: 1) individuals with DS carrying chromosome 21 copy number variants (CNVs) that interrupt exons may be protected from AVSD, because these CNVs return AVSD susceptibility loci back to disomy, and 2) individuals with DS carrying chromosome 21 genes spanned by microduplications are at greater risk for AVSD because these microduplications boost the dosage of AVSD susceptibility loci beyond a tolerable threshold. We tested 236 case individuals with DS+AVSD and 290 control individuals with DS and a normal heart using a custom microarray with dense probes tiled on chromosome 21 for array CGH. We found that neither an individual chromosome 21 CNV nor any individual gene intersected by a CNV was associated with AVSD in DS. Burden analyses revealed that African American controls had more bases covered by rare deletions than did African American cases. Inversely, we found that Caucasian cases had more genes intersected by rare duplications than did Caucasian controls. Pathway analyses indicated copy number perturbtations of genes involved in protein heterotrimerization and histone methylating proteins. Finally, we showed that previously DS+AVSD-associated common CNVs on chromosome 21 are likely false positives. This research adds to the swell of evidence indicating that DS-associated AVSD is similarly heterogeneous, as is AVSD in the euploid population.
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:Sex chromosomal abnormalities areare associated with multiple defects. In this study, we retrospectively analyzed the single nucleotide polymorphism (SNP) arrays of 186 early embryos with sex chromosomal abnormalities. using single nucleotide polymorphism (SNP) array. Among them, 52 cases of Turner syndrome, 21 cases of triple X syndrome, 35 cases of Klinefelter syndrome and 14 cases of XYY syndrome were detected. Moreover, 27 cases of mosaic sex chromosomal abnormalities were determined. Sex chromosomal deletions and duplications were found in 37 cases. Overall, our results presented a detailed manifestation of sex chromosomal abnormalities.
Project description:Purpose: Obesity is known to be a multifactorial condition that is highly heritable. There have been ~60 susceptibility loci identified, but they only account for a fraction of cases.. As copy number variations (CNVs) have been implicated in the etiology of a multitude of human disorders including obesity, here, we investigated the contribution of rare CNVs (<0.1% population frequency) in pediatric cases of obesity. Methods: We genotyped 67 pediatric patients presenting with obesity, including 22 with co-morbid developmental delay and prioritized rare CNVs at known associated loci, as well as, those impacting genes involved in energy homeostasis or related processes. Results: We identified clinically relevant or potentially clinically-relevant CNVs in 15% (10/67) of individuals. Of these, 4% (3/67) had 16p11.2 microdeletions encompassing the known obesity risk gene SH2B1. Notably, we identified two unrelated probands harboring different 6p22.2 microduplications encompassing SCGN, a potential novel candidate gene for obesity. Further, we identified other biologically relevant candidate genes for pediatric obesity including ARID5B, GPR39, PTPRN2, and HNF4G. Conclusion: We found previously reported candidate loci for obesity, and new ones, suggesting CNV analysis may assist in the diagnosis of pediatric obesity.
Project description:Purpose: Obesity is known to be a multifactorial condition that is highly heritable. There have been ~60 susceptibility loci identified, but they only account for a fraction of cases.. As copy number variations (CNVs) have been implicated in the etiology of a multitude of human disorders including obesity, here, we investigated the contribution of rare CNVs (<0.1% population frequency) in pediatric cases of obesity. Methods: We genotyped 67 pediatric patients presenting with obesity, including 22 with co-morbid developmental delay and prioritized rare CNVs at known associated loci, as well as, those impacting genes involved in energy homeostasis or related processes. Results: We identified clinically relevant or potentially clinically-relevant CNVs in 15% (10/67) of individuals. Of these, 4% (3/67) had 16p11.2 microdeletions encompassing the known obesity risk gene SH2B1. Notably, we identified two unrelated probands harboring different 6p22.2 microduplications encompassing SCGN, a potential novel candidate gene for obesity. Further, we identified other biologically relevant candidate genes for pediatric obesity including ARID5B, GPR39, PTPRN2, and HNF4G. Conclusion: We found previously reported candidate loci for obesity, and new ones, suggesting CNV analysis may assist in the diagnosis of pediatric obesity.
Project description:Purpose: Obesity is known to be a multifactorial condition that is highly heritable. There have been ~60 susceptibility loci identified, but they only account for a fraction of cases. As copy number variations (CNVs) have been implicated in the etiology of a multitude of human disorders including obesity, here, we investigated the contribution of rare CNVs (<0.1% population frequency) in pediatric cases of obesity. Methods: We genotyped 67 pediatric patients presenting with obesity, including 22 with co-morbid developmental delay and prioritized rare CNVs at known associated loci, as well as, those impacting genes involved in energy homeostasis or related processes. Results: We identified clinically relevant or potentially clinically-relevant CNVs in 15% (10/67) of individuals. Of these, 4% (3/67) had 16p11.2 microdeletions encompassing the known obesity risk gene SH2B1. Notably, we identified two unrelated probands harboring different 6p22.2 microduplications encompassing SCGN, a potential novel candidate gene for obesity. Further, we identified other biologically relevant candidate genes for pediatric obesity including ARID5B, GPR39, PTPRN2, and HNF4G. Conclusion: We found previously reported candidate loci for obesity, and new ones, suggesting CNV analysis may assist in the diagnosis of pediatric obesity.
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:Mounting evidence suggests that copy number variations (CNVs) can contribute to cancer susceptibility. The main goal of this study was to evaluate the role of germline CNVs in melanoma predisposition in high-risk melanoma families. We used genome-wide tiling comparative genomic hybridization and SNP arrays to characterize CNVs in 335 individuals (240 melanoma cases) from American melanoma-prone families (22 with germline CDKN2A or CDK4 mutations). We found that the global burden of overall CNVs (or deletions or duplications separately) was not significantly associated with case-control or CDKN2A/CDK4 mutation status after accounting for the familial dependence. However, we identified several rare CNVs that either involved known melanoma genes (e.g. PARP1, CDKN2A) or co-segregated with melanoma (duplication on 10q23.23, 3p12.2 and deletions on 8q424.3, 2q22.1) in families without mutations in known melanoma high-risk genes. Some of these CNVs were correlated with expression changes in disrupted genes based on RNASeq data from a subset of melanoma cases included in the CNV study. These results suggest that rare co-segregating CNVs may influence melanoma susceptibility in some melanoma-prone families and genes found in our study warrant further evaluation in future genetic analyses of melanoma.