title: Severe neonatal episodic laryngospasm due to de novo SCN4A mutations: a new treatable disorder.
abstract: 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.
  
  
  CONCLUSIONS
  Severe neonatal episodic laryngospasm is a new phenotype caused by a sodium channelopathy, which can be alleviated by channel blockers.
authors: Hôpital Femme Mère Enfant, 59, boulevard Pinel, 69 677 Bron Cedex, France. laurence.francois@chu-lyon.fr
authors: L
authors: L
authors: Lion-Francois
authors: C
authors: C
authors: Mignot
authors: S
authors: S
authors: Vicart
authors: V
authors: V
authors: Manel
authors: D
authors: D
authors: Sternberg
authors: P
authors: P
authors: Landrieu
authors: G
authors: G
authors: Lesca
authors: E
authors: E
authors: Broussolle
authors: T
authors: T
authors: Billette de Villemeur
authors: S
authors: S
authors: Napuri
authors: V
authors: V
authors: des Portes
authors: B
authors: B
authors: Fontaine
mesh_terms: D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007826:Laryngismus / Q000235:genetics*; D018895:Microsatellite Repeats / Q000235:genetics; D009154:Mutation / Q000235:genetics*; D062553:NAV1.4 Voltage-Gated Sodium Channel; D015222:Sodium Channels / Q000235:genetics*
chemical_list: D062553:NAV1.4 Voltage-Gated Sodium Channel; C106251:SCN4A protein, human; D015222:Sodium Channels