Congenital myasthenic syndrome is a group of conditions characterized by muscle weakness (myasthenia) that worsens with physical exertion. The muscle weakness typically begins in early childhood but can also appear in adolescence or adulthood. Facial muscles, including muscles that control the eyelids, muscles that move the eyes, and muscles used for chewing and swallowing, are most commonly affected. However, any of the muscles used for movement (skeletal muscles) can be affected in this condition. Due to muscle weakness, affected infants may have feeding difficulties.
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.