Late-onset limb-girdle muscle weakness with tubular aggregates, effective cholinesterase inhibitors and spared extraocular muscles are hallmarks of glycosylation defect-associated congenital myasthenia.

Congenital myasthenic syndromes (CMS) are heterogeneous disorders caused by germline mutations in genes encoding molecules expressed at the neuromuscular junction. In all, 14 genes (CHRNA1, CHRNB1, CHRND, CHRNE, CHRNG, RAPSN, SCN4A, MUSK, DOK7, PLEC1, LAMB2, COLQ, CHAT, AGRN) had been identified in association with CMS by 2006. All the identified molecules function exclusively at the neuromuscular junction except for choline acetyltransferase, which is also essential for cholinergic synapses in the central nervous system. …