Abstract
Congenital myasthenic syndromes (CMS) are rare autosomal recessive disorders of neuromuscular transmission. They manifest early, but although symptoms can be improved with treatment, they often remain unrecognized.
In our region, CMS with mutations of CHNE gene is well known and is particularly common in the gypsy ethnic group. However, there also are other, much more severe types, such as COLQ CMS that may be complicated by respiratory failure.
In COLO CMS, decomposition of acetylcholine at a synapse is disrupted. The synapse is overloaded and, therefore, syntostigmine as well as acetylcholinesterase inhibitors worsen the symptoms.
Ephedrine is the treatment of choice. Apnoea monitor and resuscitation training in parents can be life-saving.
In cases where both pathogenic mutations are known, prenatal or preimplantation diagnostics are available. We present three CMS patients who suffered from respiratory crises at an early age.
The outcome was variable a boy died at 6 months of age, a 7-year old girl needs nocturnal ventilation support and walks 10 meters, an adult patient has minimal sequelae. In two patients, COLQ mutations have been confirmed as a cause of CMS and COLQ CMS is suspected in the remaining patient (patient P2).