（三）少年时重症肌无力（juvenileneonatalmyastheniagravis）为后天获得性肌无力，可以查到血清中nAChR-Ab。
O O O B-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis O B-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis O O B-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis O O O O O B-bod I-bod O B-mic I-mic I-mic I-mic I-mic O O O O