WEs of parental Nalm6 cells without additional chromosome 21 (T21)
Genomic DNA was isolated the Qiagen DNeasy Blood & Tissue Kit (Qiagen). DNA concentration was determined using the DeNovix (Wilmington) and the Qubit and corresponding Qubit dsDNA broad range kit (Thermo Fischer Scientific). Subsequently, library preparation and DNA sequencing was performed by Novogene (Hong Kong, China). In short, sequencing libraries were generated using Agilent SureSelect Human All ExonV6 kit (Agilent Technologies, CA, USA). Paired-end sequencing, of 150 base pair long reads, was done on the NovaSeq6000 (Illumina), generating at least 60 million raw reads per sample.