Severe Case of Congenital Myasthenic Syndrome with Novel Mutations in MUSK

Question: Congenital myasthenic syndromes are rare conditions. So far, 18 causative genes are known. Mutations in MUSK are very rare, since the first description in 2004 only 13 patients have been reported, mostly with a relatively mild course. The molecular diagnosis has implications for the choice of treatment, and genetic counselling.