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Background. The use of chromosomal microarray analysis (CMA) in prenatal diagnosis of chromosomal and genetic diseases has resulted in a significant improvement in the diagnosis of genetically caused congenital malformations, neurodevelopmental disorders, and congenital anomalies, with a high diagnostic yield in selected prenatal cases. Objective. The objective of this study was to evaluate the application of CMA in the prenatal diagnosis of high-risk pregnant women. Method. A total of 576 pregnancies were selected from May 2018 to October 2020 in our hospital, including amniotic fluid chromosome, karyotype analysis, and CMA detection. The study group was divided into two groups based on the indications for testing: group A has 88 patients at the age of 35 years or older, and group B patients were in high-risk pregnancies, which consisted of 33 cases of bad pregnancy history, 252 high-risk serological screenings, 70 high-risk non-invasive prenatal testing (NIPT), 65 cases of B-ultrasound indicated fetal development abnormalities or ultrasonic soft marker abnormalities, and 68 other cases of pregnant women or both who have genetic or chromosomal abnormalities. At last, we have an analysis of the detection rate from different testing methods. Results. Based on the follow-up test, 576 high-risk pregnant women showed an amniotic fluid chromosome karyotype rate of 18.1% (104/576), and the remaining 472 of these cases suffered a CNV ratio of 14.2% (67/472). 472 women of low clinical relevance are at 4.87% (23/472), 16 people showed a clear cause ratio = 3.39% (16/472), and 28 of the 472 (5.93%) cases showed polymorphism. Conclusions. In our study, CMA significantly improved the fetal detection rate and diagnosis rate in high-risk pregnant women, which proved to be a very useful method in the diagnosis of genetically caused neurodevelopmental disorders and congenital anomalies. The use of CMA in high-risk pregnant women is justified, and these women can detect an additional (3.40%, 16/472) of pathogenic microdeletions and microduplications in the cases. [ABSTRACT FROM AUTHOR]

Copy number variations (CNVs) at the chromosomal 1q21.1 region represent a group of hot-spot recurrent rearrangements in human genome, which have been detected in hundreds of patients with variable clinical manifestations. Yet, report of such CNVs in prenatal scenario was relatively scattered. In this study, 17 prenatal cases involving the 1q21.1 microdeletion or duplication were recruited. The clinical survey and imaging examination were performed; and genetic detection with karyotyping and CNV analysis using chromosomal microarray (CMA) or CNVseq were subsequently carried out. These cases were all positive with 1q21.1 CNV, yet presented with exceedingly various clinical and utrasonographic indications. Among them, 12 pregnancies carried 1q21.1 deletions, while the other 5 carried 1q21.1 duplications, all of which were within the previously defined breaking point (BP) regions. According to the verification results, 9 CNVs were de novo, 7 were familial, and the other 1 was not certain. We summarized the clinical information of these cases, and the size and distribution of CNVs, and attempted to analyze the association between these two aspects. The findings in our study may provide important basis for the prenatal diagnosis and genetic counseling on such conditions in the future. [ABSTRACT FROM AUTHOR]