A severe congenital myasthenic syndrome with "dropped head" caused by novel MUSK mutations. Issue 4 (1st June 2015)

• Record Type: Journal Article
• Authors: Giarrana, Miriam L.; Joset, Pascal; Sticht, Heinrich; Robb, Stephanie; Steindl, Katharina; Rauch, Anita; Klein, Andrea
• Is Part Of: Muscle & nerve. Volume 52:Issue 4(2015:Oct.)
• Page Start: 668
• Page End: 673
• Publication Date: 2015-06-01
• Subjects: Neuromuscular diseases -- Periodicals; Muscles -- Periodicals; Nerves -- Periodicals; 616.74
• DOI: 10.1002/mus.24687
• Languages: English
• ISSNs: 0148-639X

Abstract

<abstract abstract-type="main"> <title>ABSTRACT</title> <p> <italic>Introduction:</italic> Congenital myasthenic syndromes are rare. Mutations in <italic>MUSK</italic> were first described in 2004. Thirteen patients have been reported to date, mostly with a relatively mild course. The molecular diagnosis has implications for choice of treatment and genetic counseling. <italic>Methods:</italic> Clinical course and electrophysiological, pathological, and genetic findings were assessed. <italic>Results:</italic> We describe the case of a boy with prenatal onset and severe respiratory symptoms with a persisting need for ventilation. The patient had severe bulbar symptoms, marked axial weakness causing a "dropped head, " and some facial and proximal weakness. Ophthalmoparesis developed during the first year of life. Salbutamol led to improvement, 3, 4‐diaminopyridine had a modest effect, but pyridostigmine produced deterioration. Two novel mutations in <italic>MUSK</italic> were found by whole exome sequencing. <italic>Conclusions:</italic> We expand the phenotype of congenital myasthenic syndromes with <italic>MUSK</italic> mutations, describing a more severe clinical course with prenatal onset. Predominant bulbar and respiratory weakness with facial and axial weakness and ophthalmoparesis are diagnostic clues. <italic>Muscle Nerve</italic> 52: 668–673, 2015</p> </abstract>