Novel Mutations in the KCND3-Encoded Kv4.3 K+ Channel Associated with Autopsy-Negative Sudden Unexplained Death

John R. Giudicessi, Dan Ye, Chad J. Kritzberger, Vladislav V. Nesterenko, David J. Tester, Charles Antzelevitch, Michael J. Ackerman

Research output: Contribution to journalArticlepeer-review

45 Scopus citations


Heritable arrhythmia syndromes, including Brugada syndrome (BrS) and idiopathic ventricular fibrillation (IVF), may serve as the pathogenic basis for autopsy-negative sudden unexplained death (SUD) and sudden infant death syndrome (SIDS). Emerging evidence has linked perturbations in the transient outward current (I to) conducted by the KCND3-encoded Kv4.3 pore-forming α-subunit to BrS or IVF. However, the contribution of KCND3 mutations to autopsy-negative SUD/SIDS is unknown. To investigate the potential association between KCND3 and SUD/SIDS, mutational analysis of KCND3 was conducted in 123 SUDS and 292 SIDS victims using polymerase chain reaction, denaturing high-performance liquid chromatography, and direct sequencing. Overall, one SIDS case (<1.0%) and two SUDS cases (1.6%) harbored potentially pathogenic mutations in KCND3. The novel p.Val392Ile, p.Ser530Pro, and p.Gly600Arg mutations involved highly conserved residues and were absent in 1,560 reference alleles. Although the SIDS-associated p.Ser530Pro mutation demonstrated a wild-type (WT) electrophysiological phenotype when heterologously expressed, the SUDSassociated p.Val392Ile and p.Gly600Arg mutations significantly increased peak current density at +40 mV in comparison with WT by 100.4% (P < 0.05) and 50.4% (P < 0.05), respectively. p.Val392Ile also slowed recovery from inactivation 3.6-fold, indicating a mixed electrophysiological phenotype. This is the first report indicating that KCND3 may serve as a rare genetic substrate in the pathogenesis of SUDS but not SIDS cases.

Original languageEnglish (US)
Pages (from-to)989-997
Number of pages9
JournalHuman mutation
Issue number6
StatePublished - Jun 2012


  • Arrhythmia
  • Ion channels
  • Kcnd3
  • Pediatrics
  • Sudden death

ASJC Scopus subject areas

  • Genetics
  • Genetics(clinical)


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