scholarly journals Prenatal diagnosis of cri-du-chat syndrome by SNP array: report of twelve cases and review of the literature

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Jiasun Su ◽  
Huayu Fu ◽  
Bobo Xie ◽  
Weiliang Lu ◽  
Wei Li ◽  
...  

Abstract Background Cri-du-chat syndrome (CdCS; OMIM#123450) is a classic contiguous gene syndrome caused by chromosome 5p terminal deletion (5p-), which characterized by a high-pitched cat-like cry, developmental delay, severe psychomotor, mental retardation, and dysmorphic features in infancy. Prenatal diagnosis of CdCS is difficult due to the non-specific ultrasound features. And reports using array analysis are rare. This study presented the first retrospective analysis of prenatal series of CdCS fetuses diagnosed by single nucleotide polymorphism (SNP) array in China. Case presentation A total of 35,233 pregnant women were enrolled from Jan 2014 to April 2019 in our center, there are twelve 5p- cases with abnormal sonographic signs revealed by SNP array, giving an incidence of 0.034% (12/35,233). Clinical information and molecular basis included: maternal demographics, indications for invasive testing, sonographic findings and SNP array results. Among all the 5p- cases revealed, nine cases were diagnosed by both karyotyping and SNP array, three cases were detected only by SNP array. Half of our cases (6/12) had an isolated 5p terminal deletion, which sizes ranged from 9.0 Mb to 30 Mb. The other half of cases (6/12) characterized by unbalanced translocation, with sex ratio 7:5 (female: male), when combine the clinical features observed from this study and available literature, the most frequent anomaly observed in prenatal ultrasound examination of CdCS was cerebral abnormalities, accounted for 44.4% (16/36) of the existing cases. Features that are less consistent included: choroid plexus cyst (13.8%, 5/36), single umbilical artery (13.3%, 4/30), ventricular septal defect (11.1%, 4/36), hydrops fetalis (8.3%, 3/36), ascites (8.3%, 3/36), increased NT/NF (8.3%, 3/36), absent/severely hypoplastic nasal bone (5.5%, 2/36), in order. Conclusion Prenatal findings such as cerebral abnormalities, absent/hypoplastic nasal bone, hydrops fetalis, ascites or encephalocele may act as suggestive signs of CdCS or other microdeletion/duplication syndromes. Combining typical karyotyping with chromosomal microarray analysis (CMA) is a definitive method for a precise diagnosis of CdCS and provides more accurate results in order to offer genetic counseling to families which need to deal with cryptic aberrations.

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Na Ma ◽  
Hui Xi ◽  
Jing Chen ◽  
Ying Peng ◽  
Zhengjun Jia ◽  
...  

Abstract Background Emerging studies suggest that low‐coverage massively parallel copy number variation sequencing (CNV-seq) more sensitive than chromosomal microarray analysis (CMA) for detecting low-level mosaicism. However, a retrospective back-to-back comparison evaluating accuracy, efficacy, and incremental yield of CNV-seq compared with CMA is warranted. Methods A total of 72 mosaicism cases identified by karyotyping or CMA were recruited to the study. There were 67 mosaic samples co-analysed by CMA and CNV-seq, comprising 40 with sex chromosome aneuploidy, 22 with autosomal aneuploidy and 5 with large cryptic genomic rearrangements. Results Of the 67 positive mosaic cases, the levels of mosaicism defined by CNV-seq ranged from 6 to 92% compared to the ratio from 3 to 90% by karyotyping and 20% to 72% by CMA. CNV-seq not only identified all 43 chromosomal aneuploidies or large cryptic genomic rearrangements detected by CMA, but also provided a 34.88% (15/43) increased yield compared with CMA. The improved yield of mosaicism detection by CNV-seq was largely due to the ability to detect low level mosaicism below 20%. Conclusion In the context of prenatal diagnosis, CNV-seq identified additional and clinically significant mosaicism with enhanced resolution and increased sensitivity. This study provides strong evidence for applying CNV-seq as an alternative to CMA for detection of aneuploidy and mosaic variants.


2020 ◽  
Author(s):  
Xiaorui Xie ◽  
Xiaoqing Wu ◽  
Linjuan Su ◽  
Meiying Cai ◽  
Ying Li ◽  
...  

Abstract Objective: To explore the significance and value of fetal nasal bone anomaly (absence or hypoplasia) as indications of prenatal diagnosis.Methods: A total of 102 fetuses diagnosed with nasal bone absence or hypoplasia by ultrasonography underwent chorionic, amniotic, or umbilical cord blood puncture. Single nucleotide polymorphism microarray (SNP-array) was used to analyze fetal chromosomes.Results: Of the 102 fetuses with nasal bone absence or hypoplasia, 25 (24.5%) had chromosomal abnormalities, including 15 cases of trisomy 21, one trisomy 18 case, and 9 cases of other copy number variations. Among the 52 cases with isolated nasal bone absence or hypoplasia, 7(13.5%) had chromosomal abnormalities. In 50 cases, abnormal nasal bone with additional soft markers or structural abnormalities was observed, while 18 cases (36.0%) had chromosomal abnormalities, which were significantly higher than that among the fetuses with isolated nasal bone abnormality.Conclusion: Fetal nasal bone absence or hypoplasia can be used as an indication for prenatal diagnosis. The detection rate of chromosomal abnormalities increases with additional soft markers or structural abnormalities. This study demonstrates that fetal nasal bone absence or hypoplasia is associated with micro-deletions or micro-duplications of chromosomes. Application of single nucleotide polymorphism microarray (SNP-array) technology can reduce the rate of missed prenatal diagnoses.


2020 ◽  
Author(s):  
Na Ma ◽  
Hui Xi ◽  
Jing Chen ◽  
Ying Peng ◽  
Zhengjun Jia ◽  
...  

Abstract Background: Emerging studies suggest that low‐coverage massively parallel copy number variation sequencing (CNV-seq) provide advantage in detecting low-level mosaicism compared with chromosomal microarray analysis (CMA). However, a prospective back-to-back comparison evaluating accuracy, efficacy, and incremental yield of CNV-seq compared with CMA is warranted. Methods: A total of 72 mosaicism cases identified by karyotyping or CMA were recruited in this study, and 67 samples (40 sex chromosome aneuploidy, 22 autosomal aneuploidy and 5 submicroscopic CNVs) were eventually analyzed by CNV-seq. Results: CNV-seq not only identified all 43 chromsomal aneuploidies or submicroscopic CNVs detected by CMA, but also provided a 34.88% (15/43) increased yield compared with CMA. Besides, the level of mosaicism defined by CNV-seq range from 6% to 92%. Conclusion: In the context of prenatal diagnosis, CNV-seq identified additional and clinically significant information with enhanced resolution and increased sensitivity of detecting mosaicism as compared with the CMA platform we used. This study provides strong evidence for applying CNV-seq as an alternative prenatal diagnostic test.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Jiamin Wang ◽  
Zhu Zhang ◽  
Qinqin Li ◽  
Hongmei Zhu ◽  
Yi Lai ◽  
...  

AbstractVentriculomegaly is considered to be linked to abnormal neurodevelopment outcome. The aim of this retrospective study was to investigate the current applications of chromosomal microarray analysis (CMA) in foetuses with ventriculomegaly. A total of 548 foetuses with ventriculomegaly detected by prenatal ultrasound underwent single nucleotide polymorphism (SNP) array testing and were subjected to long-term follow-up. The overall prevalence of chromosomal aberrations was 7.30% (40/548), including 4.20% (23/548) with pathogenic/likely pathogenic copy number variants. The incidence of chromosomal aberrations was significantly higher in foetuses with bilateral ventriculomegaly than in those with unilateral ventriculomegaly (10.56% vs. 5.71%, P = 0.040), in foetuses with non-isolated ventriculomegaly than in those with isolated ventriculomegaly (12.99% vs. 2.38%, P < 0.0001), and in foetuses with severe ventriculomegaly than in those with mild-to-moderate ventriculomegaly (23.08% vs. 6.51%, P = 0.005). The outcome in foetuses with mild ventriculomegaly was significantly better than in those with moderate ventriculomegaly (95.60% vs. 84.00%, P = 0.003). Thus, CMA should be regarded as the first-tier test for prenatal diagnosis of foetal ventriculomegaly, especially in foetuses with bilateral or non-isolated ventriculomegaly. The outcome of foetuses with mild ventriculomegaly is favourable; however, there is an increased risk of neurodevelopmental disabilities in foetuses with moderate ventriculomegaly.


2014 ◽  
Vol 69 (10) ◽  
pp. 613-621 ◽  
Author(s):  
Jamie O. Lo ◽  
Brian L. Shaffer ◽  
Cori D. Feist ◽  
Aaron B. Caughey

2021 ◽  
Vol 12 ◽  
Author(s):  
Sha Liu ◽  
Hongqian Liu ◽  
Jianlong Liu ◽  
Ting Bai ◽  
Xiaosha Jing ◽  
...  

BackgroundOur aim was to provide a theoretical basis for clinicians to conduct genetic counseling and choose further prenatal diagnosis methods for pregnant women who failed non-invasive prenatal screening (NIPS).MethodsA retrospective analysis was performed on pregnant women who had failed NIPS tests.ResultsAmong the 123,291 samples, 394 pregnant women did not obtain valid results due to test failures. A total of 378 pregnant women were available for follow-up, while 16 patients were lost to follow-up. Of these 378, 135 pregnant women chose further prenatal diagnosis through amniocentesis, and one case of dysplasia was recalled for postpartum chromosome testing. The incidence rate of congenital chromosomal abnormalities in those who failed the NIPS was 3.97% (15/378), which was higher than that of the chromosomal abnormalities in the common population (1.8%). Among the pregnant women who received prenatal diagnosis, the positive rates of chromosomal abnormalities in the chromosomal microarray analysis/copy number variation sequencing (CMA/CNV-seq) group and in the karyotyping group were 15.28 and 4.76%, respectively.ConclusionPrenatal diagnosis should be strongly recommended in posttest genetic counseling for pregnant women with NIPS failures. Further, high-resolution detection methods should be recommended for additional prenatal diagnoses.


2019 ◽  
Vol 157 (4) ◽  
pp. 220-226
Author(s):  
Yang Yu ◽  
Yuting Jiang ◽  
Xiaonan Hu ◽  
Hongguo Zhang ◽  
Ruizhi Liu ◽  
...  

Trisomy 18p is a rarely observed chromosomal aberration. Only 31 cases have previously been described in the literature. Trisomy 18p is associated with mild to moderate phenotypic anomalies and intellectual disability. Here, we report on a pregnant woman in whom noninvasive prenatal testing indicated a high risk of fetal trisomy 18. Prenatal diagnosis and karyotyping of the parents were performed and demonstrated that both the mother and the fetus had a derivative chromosome 15 with a segment of unknown origin. Chromosomal microarray analysis and FISH revealed a 14.9-Mb duplication of 18p and detected 3 centromeres of chromosome 18. To our knowledge, this is the first study reporting trisomy 18p due to an unbalanced translocation of 18p onto chromosome 15q showing 2-generation transmission. The results suggest that trisomy 18p can be considered a euchromatic variant.


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