. Author manuscript; available in PMC: 2011 Mar 8.

Published in final edited form as: J Mol Neurosci. 2009 Aug 18;40(1-2):143–153. doi: 10.1007/s12031-009-9229-0

Table 1.

Classification of congenital myasthenic syndrome based on the site of the defect

	Index cases
Presynaptic (8%)
ChAT deficiency^a	16
Paucity of synaptic vesicles and reduced quantal release	1
Congenital Lambert–Eaton-like	2
Other presynaptic defects	2
Synaptic space (15%)
EP AChE deficiency^a	43
Postsynaptic (78%)
Primary kinetic defect ± AChR deficiency^a	52
Primary AChR deficiency ± minor kinetic defect^a	108
Rapsyn deficiency^a	43
Dok-7 myasthenia^a	25
Na channel myasthenia^a	1
Plectin deficiency^a	2
Total	295

Classification was based on a cohort of CMS patients investigated at the Mayo Clinic between 1988 and 2008. One hundred seventeen patients had intercostal biopsies for in vitro electrophysiology and electron microscopy studies. Others were studied using DNA isolated from blood

Gene defect identified