Left-right asymmetry and cardiac looping: implications for cardiac development and congenital heart disease

Am J Med Genet. 2000 Winter;97(4):271-9. doi: 10.1002/1096-8628(200024)97:4<271::aid-ajmg1277>3.0.co;2-o.


Proper morphogenesis and positioning of internal organs requires delivery and interpretation of precise signals along the anterior-posterior, dorsal-ventral, and left-right axes. An elegant signaling cascade determines left- versus right-sided identity in visceral organs in a concordant fashion, resulting in a predictable left-right (LR) organ asymmetry in all vertebrates. The complex morphogenesis of the heart and its connections to the vasculature are particularly dependent upon coordinated LR signaling pathways. Disorganization of LR signals can result in myriad congenital heart defects that are a consequence of abnormal looping and remodeling of the primitive heart tube into a multi-chambered organ. A framework for understanding how LR asymmetric signals contribute to normal organogenesis has emerged and begins to explain the basis of many human diseases of LR asymmetry. Here we review the impact of LR signaling pathways on cardiac development and congenital heart disease.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.
  • Review

MeSH terms

  • Abnormalities, Multiple / embryology
  • Abnormalities, Multiple / genetics
  • Animals
  • Body Patterning / genetics
  • Chick Embryo
  • Fetal Heart / growth & development*
  • Fetal Heart / ultrastructure
  • Fetal Proteins / genetics
  • Fetal Proteins / physiology
  • Gene Expression Regulation, Developmental*
  • Heart / embryology
  • Heart Defects, Congenital / embryology*
  • Heart Defects, Congenital / genetics
  • Homeodomain Proteins / genetics
  • Homeodomain Proteins / physiology
  • Humans
  • Mice
  • Morphogenesis / genetics*
  • Nuclear Proteins*
  • Paired Box Transcription Factors
  • Situs Inversus / embryology
  • Situs Inversus / genetics
  • Transcription Factors / genetics
  • Transcription Factors / physiology
  • Viscera / abnormalities
  • Xenopus laevis / embryology
  • Zebrafish / embryology


  • Fetal Proteins
  • Homeodomain Proteins
  • Nuclear Proteins
  • Paired Box Transcription Factors
  • Transcription Factors
  • homeobox protein PITX1
  • homeobox protein PITX3
  • homeobox protein PITX2