Severe neonatal episodic laryngospasm due to de novo SCN4A mutations: a new treatable disorder

Neurology. 2010 Aug 17;75(7):641-5. doi: 10.1212/WNL.0b013e3181ed9e96.


Background: Myotonia is unusual in infants, and not well-known.

Methods: We describe neonatal life-threatening features of myotonia caused by de novo mutations in the muscle sodium channel gene SCN4A.

Results: Three male neonates initially displayed episodic laryngospasms, with face and limb myotonia appearing later. We found SCN4A de novo mutations in these neonates: p.Gly1306Glu in 2 unrelated cases and a novel mutation p.Ala799Ser in the third. Two patients survived their respiratory attacks and were efficiently treated by sodium channel blockers (mexiletine, carbamazepine) following diagnosis of myotonia.

Conclusion: Severe neonatal episodic laryngospasm is a new phenotype caused by a sodium channelopathy, which can be alleviated by channel blockers.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Female
  • Humans
  • Infant, Newborn
  • Laryngismus / genetics*
  • Microsatellite Repeats / genetics
  • Mutation / genetics*
  • NAV1.4 Voltage-Gated Sodium Channel
  • Sodium Channels / genetics*


  • NAV1.4 Voltage-Gated Sodium Channel
  • SCN4A protein, human
  • Sodium Channels