De novo variant in SCN4A causes neonatal sodium channel myotonia with general muscle stiffness and respiratory failure

Astrid Pechmann; Matthias Eckenweiler; David Schorling; Dimitra Stavropoulou; Hanns Lochmüller; Janbernd Kirschner

doi:10.1016/j.nmd.2019.09.001

De novo variant in SCN4A causes neonatal sodium channel myotonia with general muscle stiffness and respiratory failure

Neuromuscul Disord. 2019 Nov;29(11):907-909. doi: 10.1016/j.nmd.2019.09.001. Epub 2019 Sep 13.

Authors

Astrid Pechmann¹, Matthias Eckenweiler¹, David Schorling¹, Dimitra Stavropoulou², Hanns Lochmüller³, Janbernd Kirschner⁴

Affiliations

¹ Department of Neuropediatrics and Muscle Disorders, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Germany.
² Department of General Pediatrics, Divisions of Neonatology/Intensive Care Medicine, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Germany.
³ Department of Neuropediatrics and Muscle Disorders, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Germany; Children's Hospital of Eastern Ontario Research Institute; Division of Neurology, Department of Medicine, The Ottawa Hospital; and Brain and Mind Research Institute, University of Ottawa, Ottawa, Canada.
⁴ Department of Neuropediatrics and Muscle Disorders, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Germany; Department of Neuropediatrics, University Hospital Bonn, University of Bonn, Bonn, Germany. Electronic address: janbernd.kirschner@uniklinik-freiburg.de.

PMID: 31732390
DOI: 10.1016/j.nmd.2019.09.001

Abstract

Variants of the skeletal muscle sodium channel gene SCN4A are associated with different neuromuscular disorders including sodium channel myotonia. Here, we report an infant with a de novo variant in SCN4A presenting with neonatal onset of severe muscle stiffness with involvement of facial and eyelid muscles, and life-threatening events with respiratory failure due to severe apnoea and thorax rigidity. The boy dramatically improved in both respiratory and motor function under carbamazepine therapy.

Keywords: Muscle stiffness; Myotonia; Respiratory failure; SCN4A.

Publication types

Case Reports

MeSH terms

Elasticity
Genetic Variation*
Humans
Infant
Infant, Newborn
Male
Muscular Diseases / genetics*
Muscular Diseases / physiopathology
Muscular Diseases / therapy
Myotonia Congenita / genetics*
Myotonia Congenita / physiopathology
Myotonia Congenita / therapy
NAV1.4 Voltage-Gated Sodium Channel / genetics*
Phenotype
Respiratory Insufficiency / genetics*
Respiratory Insufficiency / physiopathology
Respiratory Insufficiency / therapy

Substances

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

Supplementary concepts

Potassium aggravated myotonia