Two KNOWN types of antibodies that cause MG. One set is found by the AChR test -- the other by the MuSK test. There are theories that many other antibodies exist for which no tests have been devised -- and that those MGers fall into the sero-negative category.

You already "get" that MG is complicated -- UNLESS you are one of the "lucky" ones who has a positive test result. Even then, you may be in for a "rough ride" because you may look perfectly NORMAL and feel perfectly WEAK and helpless.

There is only one lab in the US that runs the MuSK test -- Athena Diagnostics -- and the test is expensive. If you don't have insurance or don't have GOOD insurance, your doctor may hesitate.........