报告在１１２１例重症肌无力患者中发现家族性发病者２０例，占１．８％。男８例，女１２例，本病发病年龄较早，为９．３５±９．３８岁。尤以男性为著，为３．３８±１．６９岁，儿童期发病者占７０％（１４例）。≤９岁的年幼组中家族性重症肌无力高达３．１７％（１３／４１０）。半数以上为亲兄弟姐妹（１１例，５６％）。其中双胞胎４例（２０％），堂兄弟姐妹５例（２５％），８０％为眼型。全部患者对糖皮质激素疗法均有良好反应。 Report found in 1121 cases of myasthenia gravis in patients with familial onset were 20 cases, accounting for 1.8%. 8 males and 12 females, the age of onset of this disease is earlier, 9.35 ± 9.38 years old. Especially for men, 3.38 ± 1.69 years old, 70% of children with onset (14 cases). Familial myasthenia gravis in up to 9 years old was as high as 3.17% (13/410). More than half were siblings (11 cases, 56%). Among them, 4 were twins (20%), 5 were cousins ​​(25%) and 80% were eyes. All patients had a good response to glucocorticoid therapy.