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.
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: Only ~97% of the entire exome but read only 75% of the exome with more than 20x coverage. The enormous amount of generated data need to be filtered against previously identified variants deemed nonpathogenic and scrutinized for mutations in genes encoding EP related genes. The putative mutations must be confirmed by capillary sequencing and the non-truncating mutations examined by expression studies. Also, the cost of exome sequencing with the required bioinformatics analysis is still high.