Long-term follow-up of patients with congenital myasthenic syndrome caused by COLQ mutations

Neuromuscul Disord. 2012 Apr;22(4):318-24. doi: 10.1016/j.nmd.2011.09.002. Epub 2011 Nov 15.


Congenital myasthenic syndromes (CMS) are clinically and genetically heterogeneous inherited disorders characterized by impaired neuromuscular transmission. Mutations in the acetylcholinesterase (AChE) collagen-like tail subunit gene (COlQ) cause recessive forms of synaptic CMS with end plate AChE deficiency. We present data on 15 COLQ -mutant CMS carrying 16 different mutations (9 novel ones identified) followed-up for an average period of 10 ears. The mean age at the first examination was 19 ears old (range from 3 to 48). We report relapses during short or long-term periods characterized by worsening of muscle weakness sometimes associated with respiratory crises. All the relapses ended spontaneously or with 3-4 DAP or ephedrine with no residual impairment. The triggering factors identified were esterase inhibitors, effort, puberty or pregnancy highlighting the importance of hormonal factors. There was no genotype-phenotype correlation. At the end of the follow-up, 80% of patients were ambulant and 87% of patients had no respiratory trouble in spite of severe relapses.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetylcholinesterase / deficiency
  • Acetylcholinesterase / genetics*
  • Acetylcholinesterase / metabolism
  • Adolescent
  • Adult
  • Child
  • Child, Preschool
  • Collagen / genetics*
  • Collagen / metabolism
  • Disease Progression
  • Female
  • Follow-Up Studies
  • Genetic Association Studies
  • Humans
  • Male
  • Middle Aged
  • Muscle Proteins / genetics*
  • Muscle Proteins / metabolism
  • Mutation / genetics*
  • Myasthenic Syndromes, Congenital / diagnosis*
  • Myasthenic Syndromes, Congenital / genetics*
  • Phenotype
  • Recurrence
  • Treatment Outcome
  • Young Adult


  • Muscle Proteins
  • Collagen
  • Acetylcholinesterase
  • COLQ protein, human