My father had MG and was acetycholine receptor POSITIVE. I spent 14 years being tested, tested, tested and getting all kinds of different diagnoses. My tests for MG came back negative, but my doctors felt it was related to my father's condition.

All the symptoms described fit me. I began having trouble breathing when laying down in 2009. I currently sleep using a ventilator (cpap & bipap failed because my breathing is too shallow). I'm lucky that I can still use a regular mask instead of being trach'd.

Several years ago, Children's Hospital was conducting a research study and my blood was sent. It took over 3 years, but the results came back last year. Most tests were normal BUT a very smart doctor (not my regular one but one of his Fellows) saw that it did show a defective AGRIN gene, which causes a Congenital Myasthenic Syndrome. They said it fits ALL of my symptoms.

DING DING -- we have a winner and I am finally diagnosed.

So just because the standard MG test isn't coming back positive doesn't mean that there isn't some Myasthenic disease at play.