COL6A1 and congenital myasthenic syndrome: Furthermore, morphometric analysis of NMJs showed that both low‐ and high‐dose salbutamol induced a significant increase in postsynaptic terminal areas and compactness in Col6a1−/− mice (Figures 1G–L and S2A), coherently with reports of salbutamol beneficial effects in expanding NMJ size in animal models of congenital myasthenic syndromes (CMS).7, 8