Amish, Mennonite, and Hutterite
Genetic Disorder Database

Congenital Myasthenic Syndrome

OMIM #: #616326  (Click to access OMIM database)
Disorder: Congenital Myasthenic Syndrome 
Also known as: Myasthenic syndrome, congenital, 11, associated with acetylecholine receptor deficiency
Phenotype: early-onset muscle weakness which worsens with physical exertion, varying severity of myasthenia, feeding difficulties due to muscle weakness, possible breathing problems, awkward gait, easily fatigued 
Seen In: Amish
Old Order Mennonite
Old Colony Mennonite
Unknown/Other Mennonite

Testing is available at LHSC.


1   Old Order Mennonite  
Base Change: C>A, at nucleotide 264
Amino Acid Change: asn 88 --> lys
2   Old Order Mennonite  
Base Change: C>T, at nucleotide 328
Amino Acid Change: leu 110 --> phe
Last updated: 2018-04-19 

Müller JS, Abicht A, Burke G, Cossins J, Richard P, Baumeister SK, Stucka R, Eymard B, Hantaï D, Beeson D, Lochmüller H. (2004) The congenital myasthenic syndrome mutation RAPSN N88K derives from an ancient Indo-European founder. J Med Genet Aug;41(8):e104.
PubMed ID: 15286164 
Müller JS, Mildner G, Müller-Felber W, Schara U, Krampfl K, Petersen B, Petrova S, Stucka R, Mortier W, Bufler J, Kurlemann G, Huebner A, Merlini L, Lochmüller H, Abicht A. (2003) Rapsyn N88K is a frequent cause of congenital myasthenic syndromes in European patients. Neurology Jun 10;60(11):1805-10.
PubMed ID: 12796535 
Ohno K, Engel AG, Shen XM, Selcen D, Brengman J, Harper CM, Tsujino A, Milone M. (2002) Rapsyn mutations in humans cause endplate acetylcholine-receptor deficiency and myasthenic syndrome. Am J Hum Genet Apr;70(4):875-85.
PubMed ID: 11791205