Cookies on this website
We use cookies to ensure that we give you the best experience on our website. If you click 'Continue' we'll assume that you are happy to receive all cookies and you won't see this message again. Click 'Find out more' for information on how to change your cookie settings.

INTRODUCTION: Congenital myasthenic syndromes (CMS) usually present neonatally or in early childhood. When they present later, they may be mistaken for seronegative autoimmune myasthenia, and unnecessary immunosuppressive treatment may be administered. METHODS: Patients who met criteria for seronegative generalized myasthenia without congenital or early childhood onset, but with an affected sibling were tested for CMS associated genes using exome and Sanger sequencing. RESULTS: Four sibling pairs from nonconsanguineous families were identified. Three had mutations in the RAPSN gene, and 1 had a mutation in CHRNA1. One sibling of a pair with symptoms of fatigue but no convincing features of neuromuscular dysfunction tested negative on genetic studies. The definite CMS cases comprised 7 of 25 seronegative patients with definite generalized myasthenia in the clinic, and over half had been treated for autoimmune myasthenia. CONCLUSIONS: CMS is probably underdiagnosed in seronegative myasthenic disorders and should be considered in the differential diagnosis. Muscle Nerve 54: 721-727, 2016.

Original publication

DOI

10.1002/mus.25085

Type

Journal article

Journal

Muscle Nerve

Publication Date

10/2016

Volume

54

Pages

721 - 727

Keywords

CHRNA1, RAPSN, congenital myasthenic syndrome, genetics, myasthenia gravis, seronegative, Adolescent, Adult, Child, Diagnosis, Differential, Female, Humans, Male, Middle Aged, Myasthenic Syndromes, Congenital, Young Adult