Application of the BACs-on-Beads assay for the prenatal diagnosis of chromosomal abnormalities in Quanzhou, China

Jianlong Zhuang,Wanyu Fu,Yuying Jiang,Qi Luo,Chunling Lv,Chunnuan Chen,Yuanbai Wang,Shuhong Zeng

doi:10.1186/s12884-021-03589-9

Abstract

BackgroundAn increasing number of techniques have been used for prenatal diagnosis of genetic abnormalities. Our initial objective was to explore the value of the BACs-on-Beads (BoBs) assay for the prenatal diagnosis of aneuploidies and microdeletion/microduplication syndromes in Quanzhou, Southeast China.MethodsA total of 1409 pregnant women with high-risk factors for chromosomal abnormalities admitted to Quanzhou Women’s and Children’s Hospital were enrolled in this study. BoBs assays and karyotype analyses were conducted for all subjects. Subsequently, chromosome microarray analysis (CMA) or fluorescence in situ hybridization (FISH) was performed to validate the findings.ResultsIn this study, karyotype analysis and BoBs assay failed in 4 cases, and 2 cases, respectively. A total of 1403 cases were successfully analyzed, with success rates of 99.72% (1405/1409) and 99.85% (1407/1409) for karyotype analysis and Bobs assay, respectively. BoBs assay rapidly detected chromosomal aneuploidies in line with the karyotyping data. Additionally, 23 cases of microdeletions/microduplications were detected by BoBs assay but missed by karyotyping, including 22q11.2 microdeletions/microduplications, 5p15.32p15.33 microdeletion, Xp22.31 microdeletions/microduplications, Xq27.3 microdeletion, and Yp11.2 and Yq11.22q11.222 microduplication. In comparison with karyotyping, fewer mosaicisms were identified by BoBs assay. A high detection rate of chromosomal abnormalities was observed in the high-risk group during noninvasive prenatal testing (NIPT) (41.72%) and the abnormal ultrasound group (13.43%).ConclusionsBoBs assay can be used for the rapid and efficient prenatal diagnosis of common aneuploidies and microdeletion/microduplication syndromes. Moreover, the combined use of BoBs assay and karyotyping in prenatal diagnosis may allow for a more effective detection of chromosomal abnormalities.

Highlights

An increasing number of techniques have been used for prenatal diagnosis of genetic abnormalities
This study provides available data regarding the importance of prenatal diagnosis in the prevention and control of birth defects, and is of great significance in further supporting the application value of BoBs assay in prenatal diagnosis
23 cases of chromosome microdeletion/microduplication and 1 case of mosaicism were detected by BoBs assay but missed by karyotyping (Table 3)

Summary

Introduction

An increasing number of techniques have been used for prenatal diagnosis of genetic abnormalities. Our initial objective was to explore the value of the BACs-on-Beads (BoBs) assay for the prenatal diagnosis of aneuploidies and microdeletion/microduplication syndromes in Quanzhou, Southeast China. Microdeletion and microduplication syndromes refer to a series of genetic diseases caused by microchromosomal aberrations, which ranging from 103 to 106 bp [4]. More than 300 microdeletion and microduplication syndromes have been reported worldwide, with incidence rates ranging from 1/4000 to 1/50000 [5]. FISH (Fluorescence in situ hybridization), QF-PCR (Quantitative fluorescence PCR), BoBs, and CMA (Chromosome microarray analysis) are all diagnostic tools that can detect chromosomal microdeletions and microduplications, with high throughput detection and shorter reporting times. BoBs assay can be used to diagnose chromosomal abnormalities and microdeletions within 30 h [8]

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