design: The genomic DNA of hCEC clones was extracted from trypsinized cells using 0.3 g/L Proteinase K in 10 mM Tris pH 8.0 for 1 hr at 55C, followed by heat inactivation at 70C for 10 minutes. Genomic DNA was then enzymatically digested using NEBNext dsDNA Fragmentase for 25 minutes at 37C, followed by magnetic DNA bead cleanup using Sera-Mag Select Beads at a beas-to-lysate ratio of 2:1 by volume. Subsequently, DNA libraries were prepared with an average fragment size of 320 bp using the NEBNext Ultra II DNA Library Prep Kit for Illumina, following the manufacturers instructions. In brief, after phosphorylation, dA-Tailing and adaptor ligation of fragmented DNA, unique barcodes were added to each sample and PCR amplification was performed, followed by a bead cleanup. Quantification was performed using a Qubit 2.0 fluorometer and the Qubit dsDNA HS kit. The libraries were then sequenced on an Illumina NextSeq 500 at a target depth of 4 million reads in either paired-end mode (2 X 36 cycles) or single-end mode (1 X 75 cycles). Low-pass (~0.1-0.5X) WGS reads of hCEC were aligned to reference human genome hg38 using BWA-mem (v0.7.17) and the duplicates was removed using GATK (Genome Analysis Toolkit, v4.1.7.0) to generate analysis-ready BAM files.