To date, 34 genes are involved in congenital myasthenic syndromes (CMS), including SLC5A7. The latter encodes CHT1, a protein responsible at the presynaptic level for reuptake of acetylcholine molecules. Canadian researchers report the observation of an 11 year old patient with :
- the clinical picture was one of hypotonia and global developmental delay after the initial period of neonatal respiratory distress,
- two distinct mutations of the SLC5A7 gene (p.I294T and p.D349N) were identified,
- functional studies provided insight into why these mutations were not lethal.
The authors highlight the beneficial effects of anticholinesterase treatment in this patient.
Biochemical characterization of two novel mutations in the human high-affinity choline transporter 1 identified in a patient with congenital myasthenic syndrome. Rizvi M, Truong TK, Zhou J et al. Hum Mol Genet. 2023 Jan 5:ddac309.