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A myasthenic syndrome with congenital paucity of secondary synaptic clefts: CPSC Syndrome
Author(s) -
Smit L. M. E.,
Hageman G.,
Veldman H.,
Molenaar P. C.,
Oen B. S.,
Jennekens F. G. I.
Publication year - 1988
Publication title -
muscle and nerve
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.025
H-Index - 145
eISSN - 1097-4598
pISSN - 0148-639X
DOI - 10.1002/mus.880110410
Subject(s) - postsynaptic potential , congenital myasthenic syndrome , acetylcholine receptor , intercostal muscle , cholinesterase , synaptic cleft , medicine , pathology , myasthenia gravis , neuromuscular junction , neuroscience , receptor , biology , neurotransmission , respiratory system
Two cases of a newly recognized myasthenic syndrome were investigated (CPSC syndrome). The course of the disease was observed for periods of 6 and 3 years. In infancy, exacerbations of the symptoms occurred during febrile illness, but thereafter the clinical course was stable and the children appeared to be only slightly handicapped. Biopsies were taken from the intercostal muscle in both patients. Microelectrode studies revealed small Mepp amplitudes. Light microscopy demonstrated predominance of type I fibers and focal type‐grouping. There was a lowered cholinesterase activity and frequent branching of preterminal axons. Electron microscopy revealed that there were few, if any, folds of the postsynaptic membrane and that there were no signs of degeneration. Methods for localization of acetylcholine receptors (AChR) revealed a deficiency and altered distribution of AChRs at these postsynaptic membranes and the occurrence of extrajunctional AChRs in some muscle fibers. It is concluded that the syndrome is a clinicopathological entity, characterized morphologically by a congenital paucity of secondary synaptic clefts (CPSC syndrome).