Congenital myasthenic syndromes (CMSs) are heterogeneous disorders in which the safety margin of neuromuscular transmission is compromised by one or more mechanisms. Specific diagnosis of a CMS is important as some medications that benefit one type of CMS can be detrimental in another type. In some CMSs, strong clinical clues point to a specific diagnosis.
By identifying the genetic defects that cause CMS, MDA-funded scientists have improved the diagnosis of CMS and discovered drugs that are effective against it. They’re pursuing better drug treatments, and eyeing techniques to fix or replace the underlying genetic defects by gene therapy. n the past, people with congenital myasthenic syndromes (CMS) were often told they had myasthenia gravis (MG) and were subjected to years of pointless immunosuppressive therapy.
Statistics: 21-year-old woman had myasthenic symptoms since birth that responded poorly to anticholinesterase therapy. Tests for acetylcholine receptor (AChR) antibodies were negative. An intercostal muscle specimen was obtained to investigate the character of the neuromuscular transmission defect. There were no immune deposits at the endplates. The quantal content of the endplate potential was normal. Miniature endplate potentials and currents were very small, but the number of AChR per endplate was normal.