Congenital myasthenic syndrome by mutation of the ColQ gene: Phenotypic and evolutionary profile of three Algerian families

Background: Congenital myasthenic syndromes (CMS) are rare genetic neuromuscular disorders. The COLQ gene encoding the collagenous subunit of the acetyl cholinesterase enzyme tail is implicated in a synaptic form of CMS (also called type 5, according to the new gene table 2020 classification). Objective: To study the clinical phenotype of three families with COLQ gene mutations. Methods: We report a series of three consanguineous families, with seven affected patients, carrying three different mutations of the COLQ gene, one of which has never been reported in the literature before. Results: We studied their clinical and paraclinical phenotypes, and try to compare the three families as well as compare them with other series carrying COLQ gene mutations reported in the literature. Conclusion: COLQ gene mutations have phenotypic particularities that must be recognized to propose appropriate genetic study.