Clinical study| Volume 75, P195-198, May 2020

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Congenital myasthenic syndrome due to DOK7 mutation in a cohort of patients with ‘unexplained’ limb-girdle muscular weakness

Published:March 29, 2020DOI:


      • DOK7-CMS have phenotypic overlap with other causes of ‘unexplained’ LGMW.
      • The minimum prevalence of undiagnosed DOK7-CMS with ‘unexplained’ LGMW is 2.9%.
      • DOK7-CMS should be investigate when manifestation is an ‘unexplained’ LGMW.


      Congenital myasthenic syndromes (CMS) associated with pathogenic variants in the DOK7 gene (DOK7-CMS) have phenotypic overlap with other neuromuscular disorders associated with limb-girdle muscular weakness (LGMW). Genetic analysis of the most common mutation (c.1124_1127dupTGCC) in DOK7 was performed in 34 patients with “unexplained” LGMW associated with non-specific changes in muscle biopsy. Of the 34 patients, one patient showed the DOK7 c.1124_1127dupTGCC variant in homozygousity. Our study estimates the minimum prevalence of undiagnosed DOK7-CMS to be 2.9% in southern Brazilian patients from our centre. Our data confirm that clinicians should look for DOK7-CMS patients when the clinical manifestation is an ‘unexplained’ LGMW, mainly if associated with non-specific changes in muscle biopsy.


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