Modeling Human TBX5 Haploinsufficiency Predicts Regulatory Networks for Congenital Heart Disease

Dev Cell. 2021 Feb 8;56(3):292-309.e9. doi: 10.1016/j.devcel.2020.11.020. Epub 2020 Dec 14.


Haploinsufficiency of transcriptional regulators causes human congenital heart disease (CHD); however, the underlying CHD gene regulatory network (GRN) imbalances are unknown. Here, we define transcriptional consequences of reduced dosage of the CHD transcription factor, TBX5, in individual cells during cardiomyocyte differentiation from human induced pluripotent stem cells (iPSCs). We discovered highly sensitive dysregulation of TBX5-dependent pathways-including lineage decisions and genes associated with heart development, cardiomyocyte function, and CHD genetics-in discrete subpopulations of cardiomyocytes. Spatial transcriptomic mapping revealed chamber-restricted expression for many TBX5-sensitive transcripts. GRN analysis indicated that cardiac network stability, including vulnerable CHD-linked nodes, is sensitive to TBX5 dosage. A GRN-predicted genetic interaction between Tbx5 and Mef2c, manifesting as ventricular septation defects, was validated in mice. These results demonstrate exquisite and diverse sensitivity to TBX5 dosage in heterogeneous subsets of iPSC-derived cardiomyocytes and predicts candidate GRNs for human CHDs, with implications for quantitative transcriptional regulation in disease.

Keywords: cardiomyocyte differentiation; congenital heart disease; disease modeling; gene dosage; gene regulation; gene regulatory networks; haploinsufficiency; human induced pluripotent stem cells; single cell transcriptomics; transcription factor.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Body Patterning / genetics
  • Cell Differentiation
  • Gene Dosage
  • Gene Regulatory Networks*
  • Haploinsufficiency / genetics*
  • Heart Defects, Congenital / genetics*
  • Heart Ventricles / pathology
  • Humans
  • MEF2 Transcription Factors / metabolism
  • Mice
  • Models, Biological*
  • Mutation / genetics
  • Myocytes, Cardiac / metabolism
  • T-Box Domain Proteins / genetics*
  • Transcription, Genetic


  • MEF2 Transcription Factors
  • T-Box Domain Proteins
  • T-box transcription factor 5