New phenotype and neonatal onset of sodium channel myotonia in a child with a novel mutation of SCN4A gene

C Fusco, D Frattini, GG Salerno, E Canali… - Brain and …, 2015 - Elsevier
Myotonia is rare in newborns, and not well-known. Mutations of the skeletal muscle sodium
channel gene SCN4A are associated with several neuromuscular disorders including
sodium channel myotonias. We reported a 4-year-old female who presented with diffuse
stiffness, bilateral clubfoot, hip dislocation, facial dysmorphisms and myotonia at birth. At 4
years of age the neurological examination showed characteristic “Hercules-like
appearance” hyporeflexia, mild grip myotonia and bilateral pes cavus. The stiffness was …