DNMT3B and Down syndrome: To test this hypothesis, we generated hiPSCs from skin fibroblasts of patients with ICF (immunodeficiency, centromere instability, and facial anomalies) syndrome who carried double heterozygous point mutations in the catalytic domain of DNMT3B, and mapped the methylome for two ICF hiPSC lines at basepair resolution via whole-genome shotgun bisulfite sequencing.