Abstract
Holt-Oram syndrome (HOS), which is caused by genetic changes in the TBX5 gene, affects the hands and heart. HOS patients have heart defects, including atrial septal defects (ASD), ventricular septal defects (VSD) and heart conduction disease. Here, we generated a homozygous TBX5 knockout human embryonic stem cell (hESC) line (TBX5-KO) using a CRISPR/Cas9 system. The TBX5-KO maintained stem cell like morphology, pluripotency markers, normal karyotype, and could differentiate into all three germ layers in vivo. This cell line can provide an in vitro platform for studying the pathogenic mechanisms and biological function of TBX5 in the heart development.