Connexin43 mutation causes heterogeneous gap junction loss and sudden infant death

David W. Van Norstrand, Angeliki Asimaki, Clio Rubinos, Elena Dolmatova, Miduturu Srinivas, David J. Tester, Jeffrey E. Saffitz, Heather S. Duffy, Michael John Ackerman

Research output: Contribution to journalReview article

55 Scopus citations

Abstract

BACKGROUND-: An estimated 10% to 15% of sudden infant death syndrome (SIDS) cases may stem from channelopathy-mediated lethal arrhythmias. Loss of the GJA1-encoded gap junction channel protein connexin43 is known to underlie formation of lethal arrhythmias. GJA1 mutations have been associated with cardiac diseases, including atrial fibrillation. Therefore, GJA1 is a plausible candidate gene for premature sudden death. METHODS AND RESULTS-: GJA1 open reading frame mutational analysis was performed with polymerase chain reaction, denaturing high-performance liquid chromatography, and direct DNA sequencing on DNA from 292 SIDS cases. Immunofluorescence and dual whole-cell patch-clamp studies were performed to determine the functionality of mutant gap junctions. Immunostaining for gap junction proteins was performed on SIDS-associated paraffin-embedded cardiac tissue. Two rare, novel missense mutations, E42K and S272P, were detected in 2 of 292 SIDS cases, a 2-month-old white boy and a 3-month-old white girl, respectively. Analysis of the E42K victim's parental DNA demonstrated a de novo mutation. Both mutations involved highly conserved residues and were absent in >1000 ethnically matched reference alleles. Immunofluorescence demonstrated no trafficking abnormalities for either mutation, and S272P demonstrated wild-type junctional conductance. However, junctional conductance measurements for the E42K mutation demonstrated a loss of function not rescued by wild type. Moreover, the E42K victim's cardiac tissue demonstrated a mosaic immunostaining pattern for connexin43 protein. CONCLUSIONS-: This study provides the first molecular and functional evidence implicating a GJA1 mutation as a novel pathogenic substrate for SIDS. E42K-connexin43 demonstrated a trafficking-independent reduction in junctional coupling in vitro and a mosaic pattern of mutational DNA distribution in deceased cardiac tissue, suggesting a novel mechanism of connexin43-associated sudden death.

Original languageEnglish (US)
Pages (from-to)474-481
Number of pages8
JournalCirculation
Volume125
Issue number3
DOIs
StatePublished - Jan 24 2012

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Keywords

  • Arrhythmia
  • connexins
  • death
  • electrophysiology
  • genetics
  • sudden

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine
  • Physiology (medical)

Cite this

Van Norstrand, D. W., Asimaki, A., Rubinos, C., Dolmatova, E., Srinivas, M., Tester, D. J., Saffitz, J. E., Duffy, H. S., & Ackerman, M. J. (2012). Connexin43 mutation causes heterogeneous gap junction loss and sudden infant death. Circulation, 125(3), 474-481. https://doi.org/10.1161/CIRCULATIONAHA.111.057224