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

• Autor(a) principal: Lorenzoni,Paulo José
• Data de Publicação: 2022
• Outros Autores: 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
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Arquivos de neuro-psiquiatria (Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0004-282X2022000100069
• topic: Myasthenic Syndromes, Congenital; Myasthenia Gravis; Genetics

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.