Prenatal BACs‐on‐Beads^™: a new technology for rapid detection of aneuploidies and microdeletions in prenatal diagnosis

Abstract

Prenatal BoBs™ is a robust technology for the investigation of fetuses with normal karyotype with or without sonographic abnormalities. Running in parallel with the karyotype analysis, it can be proposed instead of rapid FISH or QF-PCR providing rapid results on common aneuploidies and additional information regarding the microdeletion syndromes.

A French multicenter study of over 700 patients with 22q11 deletions diagnosed using FISH or aCGH

“…Other techniques (such as multiplex ligation-dependent probe amplification and BACs-on-Beads) have also been developed. 25,26 These techniques enable the diagnosis of 22q11.2DS in patients with atypical phenotypes and/or who have been missed by conventional cytogenetic techniques.…”

Prenatal BoBsTM in the cytogenetic analysis of products of spontaneous miscarriage

“…This rapid targeted assay is dependent on DNA extraction and does not require live or intact cells, and represents an interesting alternative to conventional cytogenetics that require cell culture. [5,9,11,12] In our study, cell culture failure prevented standard karyotype analysis of 38 samples. However, Prenatal BoBs TM provided a conclusive result in all cases, making it a useful tool for the cytogenetic analysis of POCs, especially when culture fails.…”

“…[5] Prenatal BoBs TM is a targeted assay, so the loci of the genome that may have clinical relevance in an unbalanced state and that are not targeted by the probe set will go undetected. [5,9,11] Better coverage throughout the genome would lead to the detection of additional clinically relevant imbalances, but would also identify gains or losses of unknown or unclear clinical significance. [11,14] Moreover, Prenatal BoBs TM has some limitations in the detection of polyploidies (triploidies and tetraploidies), [5,9] which account for nearly 16% of abnormalities found by conventional karyotyping of POC.…”

“…Two assays are available, Prenatal BoBs TM for the detection of trisomy 13, 18, and 21 and the most frequent syndromes associated with microdeletions, and KaryoLite BoBs TM , which can detect aneuploidy in all chromosomes by quantifying the proximal and terminal regions of each chromosome arm. Prenatal BoBs TM has been shown to be a robust technology for the prenatal investigation of fetuses with or without abnormalities on ultrasound, [5,9] whereas KaryoLite BoBs TM has been found clinically useful for the investigation of SM products. [10] Since September 2012, Prenatal BoBs TM has been used for prenatal diagnosis in the routine clinical setting in the Medical Cytogenetic Service of the University Hospital of Clermont-Ferrand (France).…”

Bacterial artificial chromosomes (BACs)-on-Beads™ as a diagnostic platform for the rapid aneuploidy screening of products of conception

“…Cytogenetic techniques that are not dependent on actively growing tissue are becoming more common, including quantitative fluorescence (QF)-PCR (2,3), multiplex ligation-dependent probe amplification (MLPA) (4,5), molecular karyotyping (6) and bacterial artificial chromosomes (BACs)-on-Beads™ (BoBs) (7)(8)(9)(10)(11). Of these techniques, BoBs offers the ability to assess small batch sizes at a relatively low cost with comprehensive coverage of all the chromosome arms, whilst complementing the highly interrogative array-based methods that are used in molecular karyotyping.…”