Mutations in genes encoding components of the asparagine-linked protein glycosylation pathway are associated with congenital myasthenic syndromes (CMSs), a new study reveals. Cossins et al. found causative ALG2 and ALG14 mutations among a cohort of patients with a form of CMS characterized by limb-girdle myasthenia. The findings are consistent with previous data linking CMS to mutations in DPAGT1, which encodes another enzyme involved in asparagine-linked protein glycosylation.