Previous studies have shown that inhibiting AChE with OP compounds, or other circumstances in which AChE activity is compromised, triggers a focal myopathy, reported in some studies to trigger degeneration of motor nerve terminals (Leonard and Salpeter, 1979; Duxson and Vrbová, 1985; Hutchinson et al., 1993; Gomez et al., 2002). This evidence concerns the gene ACHE and myopathy.