Investigation of somatic NKX2-5, GATA4 and HAND1 mutations in patients with tetralogy of Fallot

Pathology. 2011 Jun;43(4):322-6. doi: 10.1097/PAT.0b013e32834635a9.

Abstract

Aims: Tetralogy of Fallot (TOF) is the most common type of congenital heart disease (CHD). Several genes essential for heart development have been identified. In recent years, there have been a few reports of the high frequency of somatic mutation in the heart tissues of CHD patients. The majority of findings were reported by the same investigators using formalin fixed tissues. In this study, we investigate the possibility of somatic mutation in fresh pathological cardiac tissues.

Methods: We sequenced all exons and their boundaries of the NKX2-5, GATA4 and HAND1 genes from the right ventricular outflow tract muscle and peripheral blood of 38 unrelated non-syndromic TOF children who had undergone routine surgery. The same group of genes was also sequenced in the peripheral blood of 105 control subjects. We also compared the DNA yield in different tissue storage methods and sequenced 10 formalin fixed specimens.

Results: Sequencing cardiac muscle and peripheral blood from the same patient showed identical findings. The previously reported p.Pro407Gln mutation in GATA4 gene and a novel heterozygous p.Ala58Glu mutation in HAND1 gene were identified in two of the 38 patients, both in the affected cardiac tissues and in the lymphocytes. These mutations were not seen in any control subjects. The formalin fixation rendered less DNA yield than the frozen method, but no artificial mutations were generated.

Conclusions: Our study shows no evidence of somatic NKX2-5, GATA4 and HAND1 mutations playing a role in the pathogenesis of TOF. Our findings suggest that the GATA4 and HAND1 germline mutations are associated with non-syndromic CHD.

MeSH terms

  • Basic Helix-Loop-Helix Transcription Factors / genetics*
  • Basic Helix-Loop-Helix Transcription Factors / metabolism
  • Child
  • Child, Preschool
  • Female
  • GATA4 Transcription Factor / genetics*
  • GATA4 Transcription Factor / metabolism
  • Homeobox Protein Nkx-2.5
  • Homeodomain Proteins / genetics*
  • Homeodomain Proteins / metabolism
  • Humans
  • Infant
  • Male
  • Mutation*
  • Myocardium / metabolism
  • Tetralogy of Fallot / genetics*
  • Tetralogy of Fallot / metabolism
  • Transcription Factors / genetics*
  • Transcription Factors / metabolism

Substances

  • Basic Helix-Loop-Helix Transcription Factors
  • GATA4 Transcription Factor
  • GATA4 protein, human
  • Homeobox Protein Nkx-2.5
  • Homeodomain Proteins
  • NKX2-5 protein, human
  • Transcription Factors
  • helix-loop-helix protein, eHAND