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

Non-dystrophic myotonias are a rare group of neuromuscular disorders caused by variants in skeletal muscle sodium (SCN4A) or chloride (CLCN1) channels genes. Variants in SCN4A are associated with different phenotypes such as paramyotonia congenita, hyper- or hypokalemic periodic paralysis, sodium channel myotonia but also with congenital myasthenic syndromes and congenital myopathies [1, 2]. Clinical symptoms are mainly characterized by episodes with muscle stiffness or paralysis triggered by exercise, cold, infections or fasting [2, 3].

Source: Neuromuscular Disorders - September 12, 2019 Category: Neurology Authors: Astrid Pechmann, Matthias Eckenweiler, David Schorling, Dimitra Stavropoulou, Hanns Lochm üller, Janbernd Kirschner Tags: Case report Source Type: research