Calmodulin mutations associated with recurrent cardiac arrest in infants

Lia Crotti, Christopher N. Johnson, Elisabeth Graf, Gaetano M. De Ferrari, Bettina F. Cuneo, Marc Ovadia, John Papagiannis, Michael D. Feldkamp, Subodh G. Rathi, Jennifer D. Kunic, Matteo Pedrazzini, Thomas Wieland, Peter Lichtner, Britt Maria Beckmann, Travis Clark, Christian Shaffer, D. Woodrow Benson, Stefan Kääb, Thomas Meitinger, Tim M. StromWalter J. Chazin, Peter J. Schwartz, Alfred L. George*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

262 Scopus citations


Background-: Life-threatening disorders of heart rhythm may arise during infancy and can result in the sudden and tragic death of a child. We performed exome sequencing on 2 unrelated infants presenting with recurrent cardiac arrest to discover a genetic cause. Methods and Results-: We ascertained 2 unrelated infants (probands) with recurrent cardiac arrest and dramatically prolonged QTc interval who were both born to healthy parents. The 2 parent-child trios were investigated with the use of exome sequencing to search for de novo genetic variants. We then performed follow-up candidate gene screening on an independent cohort of 82 subjects with congenital long-QT syndrome without an identified genetic cause. Biochemical studies were performed to determine the functional consequences of mutations discovered in 2 genes encoding calmodulin. We discovered 3 heterozygous de novo mutations in either CALM1 or CALM2, 2 of the 3 human genes encoding calmodulin, in the 2 probands and in 2 additional subjects with recurrent cardiac arrest. All mutation carriers were infants who exhibited life-threatening ventricular arrhythmias combined variably with epilepsy and delayed neurodevelopment. Mutations altered residues in or adjacent to critical calcium binding loops in the calmodulin carboxyl-terminal domain. Recombinant mutant calmodulins exhibited several-fold reductions in calcium binding affinity. Conclusions-: Human calmodulin mutations disrupt calcium ion binding to the protein and are associated with a life-threatening condition in early infancy. Defects in calmodulin function will disrupt important calcium signaling events in heart, affecting membrane ion channels, a plausible molecular mechanism for potentially deadly disturbances in heart rhythm during infancy.

Original languageEnglish (US)
Pages (from-to)1009-1017
Number of pages9
Issue number9
StatePublished - Mar 5 2013


  • arrhythmia
  • calcium signaling
  • death, sudden, cardiac
  • exome

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine
  • Physiology (medical)


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