Congenital myasthenic syndrome in a cohort of patients with ‘double’ seronegative myasthenia gravis

ABSTRACT Background: Congenital myasthenic syndromes (CMS) have some phenotypic overlap with seronegative myasthenia gravis (SNMG). Objective: The aim of this single center study was to assess the minimum occurrence of CMS misdiagnosed as double SNMG in a Brazilian cohort. Methods: The genetic analysis of the most common mutations in CHRNE, RAPSN, and DOK7 genes was used as the main screening tool. Results: We performed genetic analysis in 22 patients with a previous diagnosis of ‘double’ SNMG. In this study, one CMS patient was confirmed due to the presence of compound heterozygous variants in the CHRNE gene (c.130insG/p.Cys210Phe). Conclusions: This study confirmed that CMS due to CHNRE mutations can be mistaken for SNMG. In addition, our study estimated the prevalence of misdiagnosed CMS to be 4.5% in ‘double’ SNMG patients of our center. Based on our findings, genetic screening could be helpful in the diagnostic workup of patients with ‘double’ SNMG in whom differential diagnosis is recommended.

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Bibliographic Details
Main Authors: Lorenzoni,Paulo José, Ducci,Renata Dal-Pra, Arndt,Raquel Cristina, Hrysay,Nyvia Milicio Coblinski, Fustes,Otto Jesus Hernandez, Töpf,Ana, Lochmüller,Hanns, Werneck,Lineu Cesar, Kay,Cláudia Suemi Kamoi, Scola,Rosana Herminia
Format: Digital revista
Published: Academia Brasileira de Neurologia - ABNEURO 2022
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