I suffer from Myotonia (EMG positiv) wich is not MD 1 and not MD 2 and not the Isaacs syndrom and the gentesting for SCN4A and CLCN1 was without any result.
But I have these pains, stiffness and fascicualtions, too, and my dougther and three uncles (father and grandfather side) suffer from the same.
My father, witout myotonic symptoms, hat exactly the same liver problems and gallbladder full with concrements like you, and he wore a peacemaker. But noone of us has a cataract.
My liver is cystic, but still the function is good and I have no increased CK. Did you make a sonography oder MRI?
So I'm sure that there are more types of myotonia oder myotonic dystrophies.